apm821xx: 5.4: add important NAND symbols

This patch adds important NAND config symbols.
These are necessary as otherwise the devices
won't find the rootfs on the NAND chips.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>

target/linux/apm821xx/nand/config-default

@@ -31,6 +31,9 @@ CONFIG_THERMAL_HWMON=y
 CONFIG_HWMON=y
 CONFIG_SENSORS_GPIO_FAN=y
 CONFIG_CMDLINE="rootfstype=squashfs noinitrd"
+CONFIG_MTD_NAND_ECC_SW_BCH=y
+CONFIG_MTD_NAND_NDFC=y
+CONFIG_MTD_RAW_NAND=y
 CONFIG_MTD_UBI=y
 CONFIG_MTD_UBI_BEB_LIMIT=20
 CONFIG_MTD_UBI_BLOCK=y