configs: am64x_evm_a53: Enable support for building multiple dtbs

Enable all relevant configs for building multiple dtbs into a single fit
image and load the right dtb for next stage.
Signed-off-by: NLokesh Vutla <lokeshvutla@ti.com>

configs/am64x_evm_a53_defconfig

@@ -28,6 +28,7 @@ CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_SPL_STACK_R=y
 CONFIG_SPL_SEPARATE_BSS=y
 CONFIG_SPL_DMA=y
+CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_SPL_DM_MAILBOX=y
 CONFIG_SPL_DM_SPI_FLASH=y
 CONFIG_SPL_POWER_DOMAIN=y
@@ -41,6 +42,8 @@ CONFIG_CMD_MMC=y
 CONFIG_CMD_TIME=y
 CONFIG_OF_CONTROL=y
 CONFIG_SPL_OF_CONTROL=y
+CONFIG_OF_LIST="k3-am642-evm k3-am642-sk"
+CONFIG_MULTI_DTB_FIT=y
 CONFIG_SPL_MULTI_DTB_FIT=y
 CONFIG_SPL_MULTI_DTB_FIT_NO_COMPRESSION=y
 CONFIG_ENV_IS_NOWHERE=y