ramips: enable badblock table support on linksys ea7xxx devices

Use remapping only on the kernel partitions.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

target/linux/ramips/dts/mt7621_linksys_ea7xxx.dtsi

@@ -76,6 +76,11 @@
 &nand {
 	status = "okay";
 
+	mediatek,bbt;
+	mediatek,bmt-remap-range =
+		<0x180000 0x580000>,
+		<0x2980000 0x2d80000>;
+
 	partitions {
 		compatible = "fixed-partitions";
 		#address-cells = <1>;

target/linux/ramips/mt7621/config-5.10

@@ -154,6 +154,7 @@ CONFIG_MTD_NAND_CORE=y
 CONFIG_MTD_NAND_ECC=y
 CONFIG_MTD_NAND_ECC_SW_HAMMING=y
 CONFIG_MTD_NAND_MT7621=y
+CONFIG_MTD_NAND_MTK_BMT=y
 CONFIG_MTD_PHYSMAP=y
 CONFIG_MTD_RAW_NAND=y
 CONFIG_MTD_ROUTERBOOT_PARTS=y