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 <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/drm_ioctl.c

···
 		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:

include/drm/drm.h

···
 enum drm_vblank_seq_type {
 	_DRM_VBLANK_ABSOLUTE = 0x0,	/**< Wait for specific vblank sequence number */
 	_DRM_VBLANK_RELATIVE = 0x1,	/**< Wait for given number of vblanks */
+	/* bits 1-6 are reserved for high crtcs */
+	_DRM_VBLANK_HIGH_CRTC_MASK = 0x0000003e,
 	_DRM_VBLANK_EVENT = 0x4000000,   /**< Send event instead of blocking */
 	_DRM_VBLANK_FLIP = 0x8000000,   /**< Scheduled buffer swap should flip */
 	_DRM_VBLANK_NEXTONMISS = 0x10000000,	/**< If missed, wait for next vblank */
 	_DRM_VBLANK_SECONDARY = 0x20000000,	/**< Secondary display controller */
 	_DRM_VBLANK_SIGNAL = 0x40000000	/**< Send signal instead of blocking, unsupported */
 };
-#define _DRM_VBLANK_HIGH_CRTC_SHIFT 16
-#define _DRM_VBLANK_HIGH_CRTC_MASK 0x001F0000
+#define _DRM_VBLANK_HIGH_CRTC_SHIFT 1
 
 #define _DRM_VBLANK_TYPES_MASK (_DRM_VBLANK_ABSOLUTE | _DRM_VBLANK_RELATIVE)
 #define _DRM_VBLANK_FLAGS_MASK (_DRM_VBLANK_EVENT | _DRM_VBLANK_SIGNAL | \
···
 };
 
 #define DRM_CAP_DUMB_BUFFER 0x1
-#define DRM_CAP_HIGH_CRTC 0x2
+#define DRM_CAP_VBLANK_HIGH_CRTC 0x2
 
 /* typedef area */
 #ifndef __KERNEL__