[media] gspca: dubious one-bit signed bitfield

This patch changes some signed integers to unsigned because
they are not intended for negative values and sparse
is making noise about it.

Sparse gives eight of these errors:
drivers/media/usb/gspca/ov519.c:144:29: error: dubious one-bit signed bitfield
Signed-off-by: NEmil Goode <emilgoode@gmail.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/gspca/ov519.c

@@ -141,14 +141,14 @@ enum sensors {
 
 /* table of the disabled controls */
 struct ctrl_valid {
-	int has_brightness:1;
-	int has_contrast:1;
-	int has_exposure:1;
-	int has_autogain:1;
-	int has_sat:1;
-	int has_hvflip:1;
-	int has_autobright:1;
-	int has_freq:1;
+	unsigned int has_brightness:1;
+	unsigned int has_contrast:1;
+	unsigned int has_exposure:1;
+	unsigned int has_autogain:1;
+	unsigned int has_sat:1;
+	unsigned int has_hvflip:1;
+	unsigned int has_autobright:1;
+	unsigned int has_freq:1;
 };
 
 static const struct ctrl_valid valid_controls[] = {