FWU: Add Firmware Update support in BL1 for ARM platforms

This patch adds Firmware Update support for ARM platforms.

New files arm_bl1_fwu.c and juno_bl1_setup.c were added to provide
platform specific Firmware update code.

BL1 now includes mmap entry for `ARM_MAP_NS_DRAM1` to map DRAM for
authenticating NS_BL2U image(For both FVP and JUNO platform).

Change-Id: Ie116cd83f5dc00aa53d904c2f1beb23d58926555
diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index f0b3ff6..f8541c7 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -174,6 +174,8 @@
 /* TSP utility functions */
 void arm_tsp_early_platform_setup(void);
 
+/* FIP TOC validity check */
+int arm_io_is_toc_valid(void);
 
 /*
  * Mandatory functions required in ARM standard platforms