sf: Move SPI flash drivers to defconfig

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.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/configs/am43xx_evm_defconfig b/configs/am43xx_evm_defconfig
index ab0eea2..1ba1c8b 100644
--- a/configs/am43xx_evm_defconfig
+++ b/configs/am43xx_evm_defconfig
@@ -8,5 +8,6 @@
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_BAR=y
+CONFIG_SPI_FLASH_MACRONIX=y
 CONFIG_SYS_NS16550=y
 CONFIG_TI_QSPI=y