refactor(plat/imx/imx8m): make image load logic for TBBR FIP booting common

This commit makes the image load logic from imx8mm common for all
imx8m platform.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
Change-Id: Ibfe2e9cc09d198cb9e309afaf381a0237a4b82ed
diff --git a/plat/imx/imx8m/imx8mm/platform.mk b/plat/imx/imx8m/imx8mm/platform.mk
index 0d0a0f3..ac5a809 100644
--- a/plat/imx/imx8m/imx8mm/platform.mk
+++ b/plat/imx/imx8m/imx8mm/platform.mk
@@ -64,7 +64,7 @@
 				drivers/imx/usdhc/imx_usdhc.c			\
 				plat/imx/imx8m/imx8mm/imx8mm_bl2_mem_params_desc.c	\
 				plat/imx/common/imx_io_storage.c		\
-				plat/imx/imx8m/imx8mm/imx8mm_image_load.c		\
+				plat/imx/imx8m/imx8m_image_load.c		\
 				lib/optee/optee_utils.c
 endif