Fix bad QSPI partitioning

The QSPI partitioning in the vendor dtb makes it impossible to update
u-boot.

modules/boot/default.nix

@@ -48,4 +48,12 @@
   };
 
   hardware.deviceTree.name = "starfive/jh7110-starfive-visionfive-2-v1.3b.dtb";
+
+  hardware.deviceTree.overlays = [
+    # https://github.com/starfive-tech/linux/pull/99
+    {
+      name = "qspi-patch";
+      dtsFile = ./qspi-patch.dts;
+    }
+  ];
 }

modules/boot/qspi-patch.dts

@@ -0,0 +1,17 @@
+/dts-v1/;
+/plugin/;
+/ {
+    compatible = "starfive,jh7110";
+    fragment@0 {
+        target = <&qspi>;
+        __overlay__ {
+            nor_flash: flash@0 {
+                partitions {
+                    spl@0 {
+                        reg = <0x0 0x40000>;
+                    };
+                };
+            };
+        };
+    };
+};