arm: Remove apx4devkit board

This board has not been converted to CONFIG_DM_MMC by the deadline of
v2019.04, which is almost two years ago.  In addition there are other DM
migrations it is also missing.  Remove it.

Cc: Lauri Hintsala <lauri.hintsala@bluegiga.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Acked-by: Lauri Hintsala <lauri.hintsala@silabs.com<mailto:lauri.hintsala@silabs.com>>
Signed-off-by: Tom Rini <trini@konsulko.com<mailto:trini@konsulko.com>>

configs/apx4devkit_defconfig

@@ -1,50 +0,0 @@
-CONFIG_ARM=y
-CONFIG_ARCH_MX28=y
-CONFIG_SYS_TEXT_BASE=0x40002000
-CONFIG_SPL_GPIO_SUPPORT=y
-CONFIG_SPL_LIBCOMMON_SUPPORT=y
-CONFIG_SPL_LIBGENERIC_SUPPORT=y
-CONFIG_NR_DRAM_BANKS=1
-CONFIG_ENV_SIZE=0x20000
-CONFIG_ENV_OFFSET=0x120000
-CONFIG_SPL_TEXT_BASE=0x00001000
-CONFIG_TARGET_APX4DEVKIT=y
-CONFIG_SPL_SERIAL_SUPPORT=y
-CONFIG_SPL=y
-CONFIG_ENV_OFFSET_REDUND=0x180000
-CONFIG_BOOTDELAY=1
-# CONFIG_DISPLAY_BOARDINFO is not set
-CONFIG_ARCH_MISC_INIT=y
-CONFIG_BOARD_EARLY_INIT_F=y
-# CONFIG_SPL_FRAMEWORK is not set
-CONFIG_HUSH_PARSER=y
-# CONFIG_CMD_FLASH is not set
-CONFIG_CMD_MMC=y
-CONFIG_CMD_USB=y
-# CONFIG_CMD_SETEXPR is not set
-CONFIG_CMD_DHCP=y
-CONFIG_CMD_MII=y
-CONFIG_CMD_PING=y
-CONFIG_CMD_CACHE=y
-CONFIG_CMD_EXT2=y
-CONFIG_CMD_FAT=y
-CONFIG_CMD_MTDPARTS=y
-CONFIG_MTDIDS_DEFAULT="nand0=gpmi-nand"
-CONFIG_MTDPARTS_DEFAULT="mtdparts=gpmi-nand:128k(bootstrap),1024k(boot),768k(env),-(root)"
-CONFIG_CMD_UBI=y
-CONFIG_ENV_OVERWRITE=y
-CONFIG_ENV_IS_IN_NAND=y
-CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
-CONFIG_SYS_RELOC_GD_ENV_ADDR=y
-CONFIG_VERSION_VARIABLE=y
-CONFIG_MXS_GPIO=y
-CONFIG_MMC_MXS=y
-CONFIG_MTD=y
-CONFIG_MTD_RAW_NAND=y
-CONFIG_NAND_MXS=y
-CONFIG_MII=y
-CONFIG_CONS_INDEX=0
-CONFIG_USB=y
-CONFIG_USB_EHCI_HCD=y
-CONFIG_USB_STORAGE=y
-CONFIG_OF_LIBFDT=y