sunxi: add spi flash support to kernel

Some of sunxi devices have onboard SPI flash.
Enable SPI NOR support and MTD fit split in kernel config.

Signed-off-by: Oskari Lemmela <oskari@lemmela.net>

target/linux/sunxi/config-4.14

@@ -363,7 +363,14 @@ CONFIG_MMC_SUNXI=y
 CONFIG_MMU_NOTIFIER=y
 CONFIG_MODULES_TREE_LOOKUP=y
 CONFIG_MODULES_USE_ELF_REL=y
-# CONFIG_MTD is not set
+CONFIG_MTD=y
+CONFIG_MTD_SPLIT_SUPPORT=y
+CONFIG_MTD_SPLIT_FIT_FW=y
+CONFIG_MTD_OF_PARTS=y
+CONFIG_MTD_JEDECPROBE=y
+# CONFIG_MTD_IMPA7 is not set
+CONFIG_MTD_M25P80=y
+CONFIG_MTD_SPI_NOR=y
 CONFIG_MULTI_IRQ_HANDLER=y
 CONFIG_MUTEX_SPIN_ON_OWNER=y
 CONFIG_NEED_DMA_MAP_STATE=y

target/linux/sunxi/config-4.19

@@ -371,7 +371,14 @@ CONFIG_MMC_SUNXI=y
 CONFIG_MMU_NOTIFIER=y
 CONFIG_MODULES_TREE_LOOKUP=y
 CONFIG_MODULES_USE_ELF_REL=y
-# CONFIG_MTD is not set
+CONFIG_MTD=y
+CONFIG_MTD_SPLIT_SUPPORT=y
+CONFIG_MTD_SPLIT_FIT_FW=y
+CONFIG_MTD_OF_PARTS=y
+CONFIG_MTD_JEDECPROBE=y
+# CONFIG_MTD_IMPA7 is not set
+CONFIG_MTD_M25P80=y
+CONFIG_MTD_SPI_NOR=y
 CONFIG_MUTEX_SPIN_ON_OWNER=y
 CONFIG_NEED_DMA_MAP_STATE=y
 CONFIG_NEON=y