fix(stm32mp1): skip OP-TEE header check if image base is NULL

In bl2_plat_handle_post_image_load(), if the image_base of OP-TEE
header image is 0, do not call optee_header_is_valid(). This can be
the case when OP-TEE is not present in the FIP.

Signed-off-by: Yann Gautier <yann.gautier@st.com>
Change-Id: Ic2d014e59665c9efa33bbce1bf2eb3b66cd6fb26
diff --git a/plat/st/stm32mp1/bl2_plat_setup.c b/plat/st/stm32mp1/bl2_plat_setup.c
index 2ade242..4f78422 100644
--- a/plat/st/stm32mp1/bl2_plat_setup.c
+++ b/plat/st/stm32mp1/bl2_plat_setup.c
@@ -461,7 +461,8 @@
 		break;
 
 	case BL32_IMAGE_ID:
-		if (optee_header_is_valid(bl_mem_params->image_info.image_base)) {
+		if ((bl_mem_params->image_info.image_base != 0UL) &&
+		    (optee_header_is_valid(bl_mem_params->image_info.image_base))) {
 			image_info_t *paged_image_info = NULL;
 
 			/* BL32 is OP-TEE header */