fix(nxp-ddr): fix coverity issue

Check return value of mmap_add_dynamic_region().

Signed-off-by: Jiafei Pan <Jiafei.Pan@nxp.com>
Change-Id: I1317e4822f3da329185d54005f08047872b5cdce
diff --git a/drivers/nxp/ddr/phy-gen2/phy.c b/drivers/nxp/ddr/phy-gen2/phy.c
index 7dbe3a3..c8245a8 100644
--- a/drivers/nxp/ddr/phy-gen2/phy.c
+++ b/drivers/nxp/ddr/phy-gen2/phy.c
@@ -2216,10 +2216,14 @@
 
 	size = PHY_GEN2_MAX_IMAGE_SIZE;
 	image_buf = (uintptr_t)phy_gen2_fw_img_buf;
-	mmap_add_dynamic_region(phy_gen2_fw_img_buf,
+	ret = mmap_add_dynamic_region(phy_gen2_fw_img_buf,
 			phy_gen2_fw_img_buf,
 			PHY_GEN2_MAX_IMAGE_SIZE,
 			MT_MEMORY | MT_RW | MT_SECURE);
+	if (ret != 0) {
+		ERROR("Failed to add dynamic memory region.\n");
+		return ret;
+	}
 	ret = img_loadr(imem_id, &image_buf, &size);
 	if (ret != 0) {
 		ERROR("Failed to load %d firmware.\n", imem_id);