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/socfpga_cyclone5_defconfig b/configs/socfpga_cyclone5_defconfig
index 27defd3..ac7bd0b 100644
--- a/configs/socfpga_cyclone5_defconfig
+++ b/configs/socfpga_cyclone5_defconfig
@@ -13,6 +13,8 @@
 CONFIG_CMD_GPIO=y
 CONFIG_DWAPB_GPIO=y
 CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_SPANSION=y
+CONFIG_SPI_FLASH_STMICRO=y
 CONFIG_DM_ETH=y
 CONFIG_ETH_DESIGNWARE=y
 CONFIG_SYS_NS16550=y