configs: am64x_evm: Move CONFIG_SYS_MMC_ENV_DEV and CONFIG_SYS_MMC_ENV_PART to defconfig files and enable configs to save env in eMMC and FAT write.

Kconfig symbols for SYS_MMC_ENV_DEV and SYS_MMC_ENV_PART have been added by
commit 7d080773347c1f6e0e896d9284134a2a411155d6. Therefore, move the
definitions of configs to corresponding board defconfig files and enable
configs to save env in eMMC.

Also enable config for FAT write in U-Boot.

Fixes: 33b7258947f4 ("board: ti: am64x: Add board support for am64x evm")
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Link: https://lore.kernel.org/r/20210726152807.22991-5-a-govindraju@ti.com
diff --git a/configs/am64x_evm_r5_defconfig b/configs/am64x_evm_r5_defconfig
index 8ce0627..6d5c390 100644
--- a/configs/am64x_evm_r5_defconfig
+++ b/configs/am64x_evm_r5_defconfig
@@ -7,11 +7,15 @@
 CONFIG_SOC_K3_AM642=y
 CONFIG_TARGET_AM642_R5_EVM=y
 CONFIG_ENV_SIZE=0x20000
+CONFIG_ENV_OFFSET=0x680000
 CONFIG_SYS_SPI_U_BOOT_OFFS=0x80000
 CONFIG_DM_GPIO=y
 CONFIG_SPL_DM_SPI=y
 CONFIG_DEFAULT_DEVICE_TREE="k3-am642-r5-evm"
 CONFIG_SPL_TEXT_BASE=0x70000000
+CONFIG_ENV_IS_IN_MMC=y
+CONFIG_SYS_MMC_ENV_DEV=0
+CONFIG_SYS_MMC_ENV_PART=1
 CONFIG_SPL_MMC_SUPPORT=y
 CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_SPL_DRIVERS_MISC_SUPPORT=y