feat(dice): add DPE driver to measured boot

Implement a DPE specific backend within the
generic measured boot framework.

Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Change-Id: Ia3a0eac0ee6f7b4b337a93d08286613e7c8186b4
diff --git a/drivers/measured_boot/rss/rss_measured_boot.c b/drivers/measured_boot/rss/rss_measured_boot.c
index 258aa8d..c44ec73 100644
--- a/drivers/measured_boot/rss/rss_measured_boot.c
+++ b/drivers/measured_boot/rss/rss_measured_boot.c
@@ -128,7 +128,7 @@
 	while (metadata_ptr->id != RSS_MBOOT_INVALID_ID) {
 		/* Get the metadata associated with this key-oid */
 		if (metadata_ptr->pk_oid == pk_oid) {
-			if (!hash_calc_done) {
+			if (hash_calc_done == false) {
 				/* Calculate public key hash */
 				rc = crypto_mod_calc_hash(CRYPTO_MD_ID,
 							  (void *)pk_ptr,