ARM: stm32: Implement board coding on AV96

The AV96 board does exist in multiple variants. To cater for all of
them, implement board code handling. There are two GPIOs which code
the type of the board, read them out and use the value to pick the
correct device tree from an fitImage.

Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Change-Id: Iddb330b9a66500495885457cbe17edc0eacaaf43
diff --git a/configs/stm32mp15_dhcom_basic_defconfig b/configs/stm32mp15_dhcom_basic_defconfig
index c2f3a5e..12c4326 100644
--- a/configs/stm32mp15_dhcom_basic_defconfig
+++ b/configs/stm32mp15_dhcom_basic_defconfig
@@ -12,7 +12,11 @@
 CONFIG_SPL_TEXT_BASE=0x2FFC2500
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_FIT=y
+CONFIG_SPL_LOAD_FIT=y
+CONFIG_SPL_FIT_SOURCE="board/dhelectronics/dh_stm32mp1/u-boot-dhcom.its"
 CONFIG_BOOTCOMMAND="run bootcmd_stm32mp"
+CONFIG_BOARD_EARLY_INIT_F=y
+CONFIG_SPL_LEGACY_IMAGE_SUPPORT=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION=y
 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION=3
 CONFIG_SPL_I2C_SUPPORT=y