media: uvcvideo: Add D3DFMT_L8 support

Microsoft HoloLense UVC sensor uses D3DFMT instead of FOURCC when
exposing formats. This adds support for D3DFMT_L8 as exposed from
the Acer Windows Mixed Reality Headset.
Signed-off-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/uvc/uvc_driver.c

@@ -93,6 +93,11 @@ static struct uvc_format_desc uvc_fmts[] = {
 		.guid		= UVC_GUID_FORMAT_Y8,
 		.fcc		= V4L2_PIX_FMT_GREY,
 	},
+	{
+		.name		= "Greyscale 8-bit (D3DFMT_L8)",
+		.guid		= UVC_GUID_FORMAT_D3DFMT_L8,
+		.fcc		= V4L2_PIX_FMT_GREY,
+	},
 	{
 		.name		= "Greyscale 10-bit (Y10 )",
 		.guid		= UVC_GUID_FORMAT_Y10,

drivers/media/usb/uvc/uvcvideo.h

@@ -154,6 +154,11 @@
 	{ 'I',  'N',  'V',  'I', 0xdb, 0x57, 0x49, 0x5e, \
 	 0x8e, 0x3f, 0xf4, 0x79, 0x53, 0x2b, 0x94, 0x6f}
 
+#define UVC_GUID_FORMAT_D3DFMT_L8 \
+	{0x32, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, \
+	 0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
+
+
 /* ------------------------------------------------------------------------
  * Driver specific constants.
  */