plat/arm: Save BL2 descriptors to reserved memory.

On ARM platforms, the BL2 memory can be overlaid by BL31/BL32. The memory
descriptors describing the list of executable images are created in BL2
R/W memory, which could be possibly corrupted later on by BL31/BL32 due
to overlay. This patch creates a reserved location in SRAM for these
descriptors and are copied over by BL2 before handing over to next BL
image.

Also this patch increases the PLAT_ARM_MAX_BL2_SIZE for juno when TBBR
is enabled.

Fixes ARM-Software/tf-issues#626

Change-Id: I755735706fa702024b4032f51ed4895b3687377f
Signed-off-by: Sathees Balya <sathees.balya@arm.com>
diff --git a/plat/arm/css/sgi/sgi_image_load.c b/plat/arm/css/sgi/sgi_image_load.c
index 1ed219d..e52124f 100644
--- a/plat/arm/css/sgi/sgi_image_load.c
+++ b/plat/arm/css/sgi/sgi_image_load.c
@@ -11,6 +11,7 @@
 #include <common/desc_image_load.h>
 #include <plat/common/platform.h>
 
+#include <plat_arm.h>
 #include <sgi_variant.h>
 
 /*******************************************************************************
@@ -72,14 +73,11 @@
 bl_params_t *plat_get_next_bl_params(void)
 {
 	int ret;
-	bl_params_t *next_bl_params;
 
 	ret = plat_sgi_append_config_node();
 	if (ret != 0)
 		panic();
 
-	next_bl_params = get_next_bl_params_from_mem_params_desc();
-	populate_next_bl_params_config(next_bl_params);
-
-	return next_bl_params;
+	return arm_get_next_bl_params();
 }
+