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/T1042D4RDB_SDCARD_defconfig b/configs/T1042D4RDB_SDCARD_defconfig
index 80c70cc..0a3b0f8 100644
--- a/configs/T1042D4RDB_SDCARD_defconfig
+++ b/configs/T1042D4RDB_SDCARD_defconfig
@@ -4,6 +4,7 @@
 CONFIG_SPL=y
 CONFIG_SYS_EXTRA_OPTIONS="PPC_T1042,T1042D4RDB,RAMBOOT_PBL,SPL_FSL_PBL,SDCARD,T104XD4RDB,SYS_FSL_DDR4"
 CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_STMICRO=y
 CONFIG_NETDEVICES=y
 CONFIG_E1000=y
 CONFIG_SYS_NS16550=y