fix(sdei): fix a crash when attempting to bind more events than are available

You can only bind a limited number of events in each range. If you
attempt to bind more, it was crashing. This patch makes it return an
error code instead.

Change-Id: Ib19f0f0780959ded244d45349d9d6c8607255c15
Signed-off-by: Charlie Bareham <charlie.bareham@arm.com>
diff --git a/services/std_svc/sdei/sdei_main.c b/services/std_svc/sdei/sdei_main.c
index 59a1673..01cc131 100644
--- a/services/std_svc/sdei/sdei_main.c
+++ b/services/std_svc/sdei/sdei_main.c
@@ -744,7 +744,9 @@
 			return SDEI_ENOMEM;
 
 		/* The returned mapping must be dynamic */
-		assert(is_map_dynamic(map));
+		if (!is_map_dynamic(map)) {
+			return SDEI_ENOMEM;
+		}
 
 		/*
 		 * We cannot assert for bound maps here, as we might be racing