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_dyn_cfg.c b/plat/arm/common/arm_dyn_cfg.c
index a62693c..c88621e 100644
--- a/plat/arm/common/arm_dyn_cfg.c
+++ b/plat/arm/common/arm_dyn_cfg.c
@@ -45,7 +45,7 @@
 	assert(heap_addr != NULL);
 	assert(heap_size != NULL);
 
-#if defined(IMAGE_BL1) || BL2_AT_EL3
+#if defined(IMAGE_BL1) || BL2_AT_EL3 || defined(IMAGE_BL31)
 
 	/* If in BL1 or BL2_AT_EL3 define a heap */
 	static unsigned char heap[TF_MBEDTLS_HEAP_SIZE];