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/T1024QDS_DDR4_defconfig b/configs/T1024QDS_DDR4_defconfig
index 1ac9c9d..39dc0a6 100644
--- a/configs/T1024QDS_DDR4_defconfig
+++ b/configs/T1024QDS_DDR4_defconfig
@@ -3,5 +3,8 @@
 CONFIG_TARGET_T102XQDS=y
 CONFIG_SYS_EXTRA_OPTIONS="PPC_T1024,SYS_FSL_DDR4"
 CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_EON=y
+CONFIG_SPI_FLASH_STMICRO=y
+CONFIG_SPI_FLASH_SST=y
 CONFIG_SYS_NS16550=y
 CONFIG_FSL_ESPI=y