plat/arm/css/sgi: Map flash used for mem_protect

The SGI platform defines the macro PLAT_ARM_MEM_PROT_ADDR which
indicates that the platform has mitigation for cold reboot attacks.

However, the flash memory used for the mem_protect region was not
mapped. This results in a crash when an OS calls PSCI MEM_PROTECT.

To fix this map the flash region used for mem_protect.

Change-Id: Ia494f924ecfe2ce835c045689ba8f942bf0941f4
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>

plat/arm/css/sgi/include/sgi_base_platform_def.h

 /*
- * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2020, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -39,7 +39,7 @@
 #  define PLAT_SP_IMAGE_MAX_XLAT_TABLES	10
 # else
 #  define PLAT_ARM_MMAP_ENTRIES		(5 + ((CSS_SGI_CHIP_COUNT - 1) * 3))
-#  define MAX_XLAT_TABLES		(5 + ((CSS_SGI_CHIP_COUNT - 1) * 3))
+#  define MAX_XLAT_TABLES		(6 + ((CSS_SGI_CHIP_COUNT - 1) * 3))
 # endif
 #elif defined(IMAGE_BL32)
 # define PLAT_ARM_MMAP_ENTRIES		8

plat/arm/css/sgi/sgi_plat.c

 /*
- * Copyright (c) 2018-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2018-2020, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -43,6 +43,9 @@ const mmap_region_t plat_arm_mmap[] = {
 const mmap_region_t plat_arm_mmap[] = {
 	ARM_MAP_SHARED_RAM,
 	SGI_MAP_FLASH0_RO,
+#ifdef PLAT_ARM_MEM_PROT_ADDR
+	ARM_V2M_MAP_MEM_PROTECT,
+#endif
 	CSS_SGI_MAP_DEVICE,
 	SOC_CSS_MAP_DEVICE,
 	ARM_MAP_NS_DRAM1,
@@ -63,6 +66,9 @@ const mmap_region_t plat_arm_mmap[] = {
 	ARM_MAP_SHARED_RAM,
 	V2M_MAP_IOFPGA,
 	CSS_SGI_MAP_DEVICE,
+#ifdef PLAT_ARM_MEM_PROT_ADDR
+	ARM_V2M_MAP_MEM_PROTECT,
+#endif
 	SOC_CSS_MAP_DEVICE,
 #if SPM_MM
 	ARM_SPM_BUF_EL3_MMAP,