lib: aarch64: fix non-code symbol errors flagged by armlink

This patch modifies the code to turn __1printf and __2printf into proper
functions to fix the following errors flagged by armlink.

Error: L6318W: backtrace.o(.text.backtrace) contains branch to a non-code symbol __2printf.
Error: L6318W: backtrace.o(.text.backtrace) contains branch to a non-code symbol __2printf.
Error: L6318W: backtrace.o(.text.backtrace) contains branch to a non-code symbol __2printf.
Error: L6318W: backtrace.o(.text.backtrace) contains branch to a non-code symbol __2printf.
Error: L6318W: backtrace.o(.text.backtrace) contains branch to a non-code symbol __2printf.
Error: L6318W: backtrace.o(.text.backtrace) contains branch to a non-code symbol __2printf.

Change-Id: I89126bc2b9db44ce8b8fc9fb1e3fc4c8c60c47a4
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

lib/aarch64/armclang_printf.S

 /*
- * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -13,7 +13,13 @@
 	.globl __2printf
 
 func __0printf
-__1printf:
-__2printf:
-        b	printf
+	b	printf
 endfunc __0printf
+
+func __1printf
+	b	printf
+endfunc __1printf
+
+func __2printf
+	b	printf
+endfunc __2printf