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/turris_omnia_defconfig b/configs/turris_omnia_defconfig
index 4a1e23c..8de522e 100644
--- a/configs/turris_omnia_defconfig
+++ b/configs/turris_omnia_defconfig
@@ -41,6 +41,7 @@
 CONFIG_ATSHA204A=y
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_MV=y
+CONFIG_SPI_FLASH=y
 CONFIG_PHY_MARVELL=y
 CONFIG_PHY_GIGE=y
 CONFIG_MVNETA=y