drm/vblank: update recently added vbl interface to be more future proof.

This makes the interface a bit cleaner by leaving a single gap in the
vblank bit space instead of creating two gaps.

Suggestions from Michel on mailing list/irc.

Reviewed-by: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 3617b4c..904d7e9 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -280,7 +280,7 @@
 		if (dev->driver->dumb_create)
 			req->value = 1;
 		break;
-	case DRM_CAP_HIGH_CRTC:
+	case DRM_CAP_VBLANK_HIGH_CRTC:
 		req->value = 1;
 		break;
 	default: