patches/openwrt: p2020: enable CONFIG_MTD_NAND_FSL_ELBC

This enables NAND controller, which is defined in the Turris 1.x device
tree. [1] More about this kernel option can be found here [2].

[1] https://github.com/torvalds/linux/blob/1c23f9e627a7b412978b4e852793c5e3c3efc555/arch/powerpc/boot/dts/turris1x.dts#L307

[2] https://cateee.net/lkddb/web-lkddb/MTD_NAND_FSL_ELBC.html

patches/openwrt/5.15-kernel-configuration/0026-enable-mtd-nand-for-p2020-config.patch

+From 5943e623fd01f7c8ad74f0b6f877cc0108b4792f Mon Sep 17 00:00:00 2001
+From: Josef Schlehofer <pepe.schlehofer@gmail.com>
+Date: Sat, 27 Aug 2022 11:46:47 +0200
+Subject: [PATCH] enable CONFIG_MTD_NAND_FSL_ELBC
+
+---
+ target/linux/mpc85xx/p2020/config-default | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/target/linux/mpc85xx/p2020/config-default b/target/linux/mpc85xx/p2020/config-default
+index ef32280dac..5093f2bc6e 100644
+--- a/target/linux/mpc85xx/p2020/config-default
++++ b/target/linux/mpc85xx/p2020/config-default
+@@ -7,6 +7,10 @@ CONFIG_GENERIC_TBSYNC=y
+ CONFIG_IRQ_DOMAIN_HIERARCHY=y
+ CONFIG_IRQ_DOMAIN_NOMAP=y
+ CONFIG_LOCK_SPIN_ON_OWNER=y
++CONFIG_MTD_CFI=y
++CONFIG_MTD_NAND_BCH=y
++CONFIG_MTD_NAND_ECC_BCH=y
++CONFIG_MTD_NAND_FSL_ELBC=y
+ CONFIG_MTD_PHYSMAP=y
+ CONFIG_MUTEX_SPIN_ON_OWNER=y
+ CONFIG_NET_FLOW_LIMIT=y
+-- 
+2.34.1
+