pinwheel: Fix webcam frame drops and raise resolution to 1080p

With the default 6 icamerasrc buffers the camera HAL ran out of pending
requests and dropped every fourth sensor frame, capping output at ~22.5 fps.
Using 10 buffers keeps the request queue fed and restores 30 fps.

hosts/pinwheel/modules/webcam/default.nix

@@ -33,6 +33,12 @@
     platform = "ipu6epmtl";
   };
 
+  services.v4l2-relayd.instances.ipu6.input = {
+    pipeline = lib.mkForce "icamerasrc buffer-count=10";
+    width = 1920;
+    height = 1080;
+  };
+
   systemd.services.v4l2-relayd-ipu6 = {
     preStart = lib.mkOverride 40 ''
       mkdir -p "$(dirname "$V4L2_DEVICE_FILE")"