Add console_core_flush() in upstream platforms

It is needed to add placeholders for this function because, as this is
not a `plat_xxx()` function, there aren't weak definitions of it in any
file.

If `console_flush()` is used and there isn't an implementation of
`console_core_flush()` in any file, the compilation will fail.

Change-Id: I50eb56d085c4c9fbc85d40c343e86af6412f3020
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

drivers/cadence/uart/aarch64/cdns_console.S

 /*
- * Copyright (c) 2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -31,9 +31,10 @@
 #include <asm_macros.S>
 #include <cadence/cdns_uart.h>
 
-        .globl  console_core_init
-        .globl  console_core_putc
-        .globl  console_core_getc
+	.globl  console_core_init
+	.globl  console_core_putc
+	.globl  console_core_getc
+	.globl	console_core_flush
 
 	/* -----------------------------------------------
 	 * int console_core_init(unsigned long base_addr,
@@ -125,3 +126,18 @@ getc_error:
 	mov	w0, #-1
 	ret
 endfunc console_core_getc
+
+	/* ---------------------------------------------
+	 * int console_core_flush(uintptr_t base_addr)
+	 * Function to force a write of all buffered
+	 * data that hasn't been output.
+	 * In : x0 - console base address
+	 * Out : return -1 on error else return 0.
+	 * Clobber list : x0, x1
+	 * ---------------------------------------------
+	 */
+func console_core_flush
+	/* Placeholder */
+	mov	w0, #0
+	ret
+endfunc console_core_flush

drivers/ti/uart/aarch64/16550_console.S

 /*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -35,6 +35,7 @@
 	.globl	console_core_init
 	.globl	console_core_putc
 	.globl	console_core_getc
+	.globl	console_core_flush
 
 	/* -----------------------------------------------
 	 * int console_core_init(unsigned long base_addr,
@@ -153,3 +154,18 @@ getc_error:
 	mov	w0, #-1
 	ret
 endfunc console_core_getc
+
+	/* ---------------------------------------------
+	 * int console_core_flush(uintptr_t base_addr)
+	 * Function to force a write of all buffered
+	 * data that hasn't been output.
+	 * In : x0 - console base address
+	 * Out : return -1 on error else return 0.
+	 * Clobber list : x0, x1
+	 * ---------------------------------------------
+	 */
+func console_core_flush
+	/* Placeholder */
+	mov	w0, #0
+	ret
+endfunc console_core_flush

plat/mediatek/common/drivers/uart/8250_console.S

 /*
- * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -33,6 +33,7 @@
 	.globl	console_core_init
 	.globl	console_core_putc
 	.globl	console_core_getc
+	.globl	console_core_flush
 
 	/* -----------------------------------------------
 	 * int console_core_init(unsigned long base_addr,
@@ -170,3 +171,18 @@ getc_error:
 	mov	w0, #-1
 	ret
 endfunc console_core_getc
+
+	/* ---------------------------------------------
+	 * int console_core_flush(uintptr_t base_addr)
+	 * Function to force a write of all buffered
+	 * data that hasn't been output.
+	 * In : x0 - console base address
+	 * Out : return -1 on error else return 0.
+	 * Clobber list : x0, x1
+	 * ---------------------------------------------
+	 */
+func console_core_flush
+	/* Placeholder */
+	mov	w0, #0
+	ret
+endfunc console_core_flush