drm: update VIA driver to 2.7.2

Add PCI DMA blitengine to VIA DRM
Add portability code for porting VIA to FreeBSD.
Sync via_drm.h with 3d driver

From: Thomas Hellstrom <unichrome@shipmail.org>, Eric Anholt <anholt@freebsd.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/drm/drm_os_linux.h b/drivers/char/drm/drm_os_linux.h
index d51aeb4..695115d 100644
--- a/drivers/char/drm/drm_os_linux.h
+++ b/drivers/char/drm/drm_os_linux.h
@@ -13,6 +13,7 @@
 #define DRM_ERR(d)			-(d)
 /** Current process ID */
 #define DRM_CURRENTPID			current->pid
+#define DRM_SUSER(p)			capable(CAP_SYS_ADMIN)
 #define DRM_UDELAY(d)			udelay(d)
 /** Read a byte from a MMIO region */
 #define DRM_READ8(map, offset)		readb(((void __iomem *)(map)->handle) + (offset))