feat(fvp_r): configure system registers to boot rich OS

Following system registers are modified before exiting EL2 to allow
u-boot/Linux to boot
  1. CNTHCTL_EL2.EL1PCTEN -> 1
     Allows U-boot to use physical counters at EL1
  2. VTCR_EL2.MSA -> 1
     Enables VMSA at EL1, which is required by U-Boot and Linux.
  3. HCR_EL2.APK = 1 & HCR_EL2.API = 1
     Disables PAuth instruction and register traps in EL1

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I58f45b6669a9ad1debb80265b243015c054a9bb1
diff --git a/plat/arm/board/fvp_r/fvp_r_bl1_context_mgmt.c b/plat/arm/board/fvp_r/fvp_r_bl1_context_mgmt.c
index 7ae853b..c6544b4 100644
--- a/plat/arm/board/fvp_r/fvp_r_bl1_context_mgmt.c
+++ b/plat/arm/board/fvp_r/fvp_r_bl1_context_mgmt.c
@@ -15,7 +15,7 @@
 #include <plat/common/platform.h>
 
 
-void cm_prepare_el2_exit(uint32_t security_state);
+void cm_prepare_el2_exit(void);
 
 /* Following contains the cpu context pointers. */
 static void *bl1_cpu_context_ptr[2];
@@ -81,6 +81,9 @@
 	/* Allow platform to make change */
 	bl1_plat_set_ep_info(image_id, next_bl_ep);
 
+	/* Prepare context for the next EL */
+	cm_prepare_el2_exit();
+
 	/* Indicate that image is in execution state. */
 	desc->state = IMAGE_STATE_EXECUTED;