There are already Kconfig options for SPI flash drivers, but we
have not moved them from config.h to defconfig files. This commit
does this in a batch.
CONFIG_ARM=y
CONFIG_TARGET_MX28EVK=y
CONFIG_SPL=y
CONFIG_SYS_EXTRA_OPTIONS="ENV_IS_IN_NAND"
# CONFIG_CMD_IMLS is not set
# CONFIG_CMD_FLASH is not set
CONFIG_CMD_GPIO=y
CONFIG_SPI_FLASH=y
CONFIG_SPI_FLASH_SST=y
