services/spm: Fix service UUID lookup

The spm_sp_get_by_uuid() function is used to look up the secure
partition that provides a given service.

Within this function, memcmp() is used to compare the service
UUIDs but it uses the size of the rdsvc->uuid pointer instead of
the size of its content (missing dereference). This means that only
a partial comparison is performed as UUIDs are 128 bits in length and
rdsvc->uuid is a uint32_t typed pointer.

Instead, use the size of the array pointed to by the svc_uuid parameter,
which will be the full 128 bits, for the comparison.

Change-Id: I258fb0cca3bf19f97b8f2a4c133981647cd050e4
Signed-off-by: Paul Beesley <paul.beesley@arm.com>

services/std_svc/spm/spm_main.c

@@ -104,7 +104,7 @@ sp_context_t *spm_sp_get_by_uuid(const uint32_t (*svc_uuid)[4])
 		     rdsvc = rdsvc->next) {
 			uint32_t *rd_uuid = (uint32_t *)(rdsvc->uuid);
 
-			if (memcmp(rd_uuid, svc_uuid, sizeof(rd_uuid)) == 0) {
+			if (memcmp(rd_uuid, svc_uuid, sizeof(*svc_uuid)) == 0) {
 				return sp_ctx;
 			}
 		}