ramips: use all reserved space for HiWiFi HC5962

These stock partitons: "backup", "hw_panic", "overly", firmware_backup", "opt"
do not contain any device-specific data and can be used for /overlay, resulting in
121M space
Signed-off-by: DENG Qingfang <dengqf6@mail2.sysu.edu.cn>

target/linux/ramips/dts/mt7621_hiwifi_hc5962.dts

@@ -44,6 +44,22 @@
 			linux,code = <KEY_RESTART>;
 		};
 	};
+
+	ubi-concat {
+		compatible = "mtd-concat";
+		devices = <&ubipart0 &ubipart1>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			ubi@0 {
+				label = "ubi";
+				reg = <0x0 0x79c0000>;
+			};
+		};
+	};
 };
 
 &nand {
@@ -77,15 +93,9 @@
 			reg = <0x140000 0x400000>;
 		};
 
-		partition@540000 {
-			label = "ubi";
-			reg = <0x540000 0x1c00000>;
-		};
-
-		partition@2140000 {
-			label = "hw_panic";
-			reg = <0x2140000 0x80000>;
-			read-only;
+		ubipart0: partition@540000 {
+			label = "ubipart0";
+			reg = <0x540000 0x1c80000>;
 		};
 
 		partition@21c0000 {
@@ -94,30 +104,9 @@
 			read-only;
 		};
 
-		partition@2240000 {
-			label = "backup";
-			reg = <0x2240000 0x80000>;
-			read-only;
-		};
-
-		partition@22c0000 {
-			label = "overly";
-			reg = <0x22c0000 0x1000000>;
-		};
-
-		partition@32c0000 {
-			label = "firmware_backup";
-			reg = <0x32c0000 0x2000000>;
-		};
-
-		partition@52c0000 {
-			label = "oem";
-			reg = <0x52c0000 0x200000>;
-		};
-
-		partition@54c0000 {
-			label = "opt";
-			reg = <0x54c0000 0x2ac0000>;
+		ubipart1: partition@2240000 {
+			label = "ubipart1";
+			reg = <0x2240000 0x5d40000>;
 		};
 	};
 };

target/linux/ramips/mt7621/config-5.4

@@ -217,6 +217,7 @@ CONFIG_MTD_UBI_BLOCK=y
 # CONFIG_MTD_UBI_FASTMAP is not set
 # CONFIG_MTD_UBI_GLUEBI is not set
 CONFIG_MTD_UBI_WL_THRESHOLD=4096
+CONFIG_MTD_VIRT_CONCAT=y
 # CONFIG_MTK_HSDMA is not set
 CONFIG_NEED_DMA_MAP_STATE=y
 CONFIG_NET_DEVLINK=y