macOS: fix warning about unkown GPU with Apple M1 chip

source/blender/gpu/GPU_platform.h

@@ -34,6 +34,7 @@ typedef enum eGPUDeviceType {
   GPU_DEVICE_ATI = (1 << 1),
   GPU_DEVICE_INTEL = (1 << 2),
   GPU_DEVICE_INTEL_UHD = (1 << 3),
+  GPU_DEVICE_APPLE = (1 << 3),
   GPU_DEVICE_SOFTWARE = (1 << 4),
   GPU_DEVICE_UNKNOWN = (1 << 5),
   GPU_DEVICE_ANY = (0xff),

source/blender/gpu/opengl/gl_backend.cc

@@ -96,6 +96,11 @@ void GLBackend::platform_init()
     GPG.device = GPU_DEVICE_SOFTWARE;
     GPG.driver = GPU_DRIVER_SOFTWARE;
   }
+  else if (strstr(vendor, "Apple")) {
+    /* Apple Silicon. */
+    GPG.device = GPU_DEVICE_APPLE;
+    GPG.driver = GPU_DRIVER_OFFICIAL;
+  }
   else if (strstr(renderer, "Apple Software Renderer")) {
     GPG.device = GPU_DEVICE_SOFTWARE;
     GPG.driver = GPU_DRIVER_SOFTWARE;