Adds option to read ROTPK from registers for FVP

Enables usage of ARM_ROTPK_LOCATION=regs for FVP board.
Removes hard-coded developer keys. Instead, setting
ARM_ROTPK_LOCATION=devel_* takes keys from default directory.
In case of ROT_KEY specified - generates a new hash and replaces the
original.

Note: Juno board was tested by original feature author and was not tested
for this patch since we don't have access to the private key. Juno
implementation was moved to board-specific file without changing
functionality. It is not known whether byte-swapping is still needed
for this platform.

Change-Id: I0fdbaca0415cdcd78f3a388551c2e478c01ed986
Signed-off-by: Max Shvetsov <maksims.svecovs@arm.com>
diff --git a/plat/arm/board/juno/platform.mk b/plat/arm/board/juno/platform.mk
index bd6bae5..a85ad53 100644
--- a/plat/arm/board/juno/platform.mk
+++ b/plat/arm/board/juno/platform.mk
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -91,6 +91,11 @@
 BL1_SOURCES		+=	drivers/arm/css/sds/sds.c
 endif
 
+ifeq (${TRUSTED_BOARD_BOOT}, 1)
+BL1_SOURCES		+=	plat/arm/board/juno/juno_trusted_boot.c
+BL2_SOURCES		+=	plat/arm/board/juno/juno_trusted_boot.c
+endif
+
 endif
 
 ifneq (${RESET_TO_BL31},0)