configs: Move CONFIG_SPI_FLASH into defconfigs

Completely move CONFIG_SPI_FLASH from remaining board header files to
defconfigs

Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com> #zynq-microzed
diff --git a/configs/rock_defconfig b/configs/rock_defconfig
index 36e35eb..2de51e8 100644
--- a/configs/rock_defconfig
+++ b/configs/rock_defconfig
@@ -40,6 +40,7 @@
 CONFIG_LED=y
 CONFIG_MMC_DW=y
 CONFIG_MMC_DW_ROCKCHIP=y
+CONFIG_SPI_FLASH=y
 CONFIG_PINCTRL=y
 CONFIG_DM_PMIC=y
 # CONFIG_SPL_PMIC_CHILDREN is not set