matroxfb: set FBINFO_READS_FAST

Set FBINFO_READS_FAST so that the console code uses scrolling instead of
rewriting. This improves scrolling speed.

A time to do ls -la /usr/bin:
	original patched
32bpp	5.4	3.6
24bpp	5.1	3.0
16bpp	4.9	2.5
8bpp	4.9	2.0
Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/matrox/matroxfb_base.c

@@ -1773,7 +1773,8 @@ static int initMatrox2(struct matrox_fb_info *minfo, struct board *b)
 				      FBINFO_HWACCEL_FILLRECT |  /* And fillrect */
 				      FBINFO_HWACCEL_IMAGEBLIT | /* And imageblit */
 				      FBINFO_HWACCEL_XPAN |      /* And we support both horizontal */
-				      FBINFO_HWACCEL_YPAN;       /* And vertical panning */
+				      FBINFO_HWACCEL_YPAN |      /* And vertical panning */
+				      FBINFO_READS_FAST;
 	minfo->video.len_usable &= PAGE_MASK;
 	fb_alloc_cmap(&minfo->fbcon.cmap, 256, 1);