V4L/DVB (12239): em28xx: fix webcam scaling

While trying to fix an mt9v001 webcam, I noticed that HSCALE/VSCALE do
work with em28xx + webcam. The issue is that the scaling setup depends
on the number of visible rows/cols of the input image.

With mt9v011 (Silvercrest), the resolution is 640x480. So, the scaling
is different from a normal TV image (720x480 on NTSC). This were causing
a wrong scaling and a previous patch disabled scaling.

As each sensor have their different resolution setting, the xres/yres
should be adjusted accordingly with the input sensor.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/em28xx/em28xx-cards.c b/drivers/media/video/em28xx/em28xx-cards.c
index 1318766..d4a7e60 100644
--- a/drivers/media/video/em28xx/em28xx-cards.c
+++ b/drivers/media/video/em28xx/em28xx-cards.c
@@ -58,8 +58,6 @@
 module_param_array(card,  int, NULL, 0444);
 MODULE_PARM_DESC(card,     "card type");
 
-#define MT9V011_VERSION                 0x8243
-
 /* Bitmask marking allocated devices from 0 to EM28XX_MAXBOARDS */
 static unsigned long em28xx_devused;
 
@@ -1730,10 +1728,12 @@
 	version = be16_to_cpu(version_be);
 
 	switch (version) {
-	case MT9V011_VERSION:
+	case 0x8243:		/* mt9v011 640x480 1.3 Mpix sensor */
 		dev->model = EM2820_BOARD_SILVERCREST_WEBCAM;
 		sensor_name = "mt9v011";
 		dev->em28xx_sensor = EM28XX_MT9V011;
+		dev->sensor_xres = 640;
+		dev->sensor_yres = 480;
 		break;
 	default:
 		printk("Unknown Micron Sensor 0x%04x\n", be16_to_cpu(version));