feat(fvp): add crypto support in BL31

DRTM implementation needs crypto support in BL31 to calculate
hash of various DRTM components

Signed-off-by: Manish V Badarkhe <manish.badarkhe@arm.com>
Change-Id: I659ce8e54550946db253d23f150cca8b2fa7b880
diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index bd59ec0..5dda485 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -419,11 +419,12 @@
     BL2_SOURCES		+= 	${EVENT_LOG_SOURCES}
 endif
 
-ifneq ($(filter 1,${MEASURED_BOOT} ${TRUSTED_BOARD_BOOT}),)
+ifneq ($(filter 1,${MEASURED_BOOT} ${TRUSTED_BOARD_BOOT} ${DRTM_SUPPORT}),)
     CRYPTO_SOURCES	:=	drivers/auth/crypto_mod.c 	\
 				lib/fconf/fconf_tbbr_getter.c
     BL1_SOURCES		+=	${CRYPTO_SOURCES}
     BL2_SOURCES		+=	${CRYPTO_SOURCES}
+    BL31_SOURCES	+=	drivers/auth/crypto_mod.c
 
     # We expect to locate the *.mk files under the directories specified below
     ifeq (${ARM_CRYPTOCELL_INTEG},0)