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/P1010RDB-PA_36BIT_NOR_SECBOOT_defconfig b/configs/P1010RDB-PA_36BIT_NOR_SECBOOT_defconfig
index b6da149..c09e73e 100644
--- a/configs/P1010RDB-PA_36BIT_NOR_SECBOOT_defconfig
+++ b/configs/P1010RDB-PA_36BIT_NOR_SECBOOT_defconfig
@@ -3,6 +3,7 @@
 CONFIG_TARGET_P1010RDB=y
 CONFIG_SYS_EXTRA_OPTIONS="P1010RDB_PA,36BIT,SECURE_BOOT"
 CONFIG_SPI_FLASH=y
+CONFIG_SPI_FLASH_SPANSION=y
 CONFIG_NETDEVICES=y
 CONFIG_E1000=y
 CONFIG_SYS_NS16550=y