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/koelsch_defconfig b/configs/koelsch_defconfig
index 848aa55..fc8a567 100644
--- a/configs/koelsch_defconfig
+++ b/configs/koelsch_defconfig
@@ -19,3 +19,4 @@
 CONFIG_SH_SDHI=y
 CONFIG_SPI_FLASH=y
 CONFIG_SPI_FLASH_BAR=y
+CONFIG_SPI_FLASH_SPANSION=y