dri2: Add vdpau driver name entry

[Maarten Lankhorst]

libvdpau has a driver loading mechanism that looks for a dri2 driver
first before falling back to nvidia, so lets use that.

Allows use of libvdpau_rx00 without having to set things up separately,
similar to the patch to xf86-video-nouveau.

Signed-off-by: Maarten Lankhorst <m.b.lankhorst at gmail.com>

diff --git a/src/radeon_dri2.c b/src/radeon_dri2.c
index 46573a7..88117a5 100644
--- a/src/radeon_dri2.c
+++ b/src/radeon_dri2.c
@@ -1299,7 +1299,7 @@ radeon_dri2_screen_init(ScreenPtr pScreen)
     DRI2InfoRec dri2_info = { 0 };
 #ifdef USE_DRI2_SCHEDULING
     RADEONEntPtr pRADEONEnt   = RADEONEntPriv(pScrn);
-    const char *driverNames[1];
+    const char *driverNames[2];
     Bool scheduling_works = TRUE;
 #endif
 
@@ -1364,9 +1364,9 @@ radeon_dri2_screen_init(ScreenPtr pScreen)
         dri2_info.ScheduleSwap = radeon_dri2_schedule_swap;
         dri2_info.GetMSC = radeon_dri2_get_msc;
         dri2_info.ScheduleWaitMSC = radeon_dri2_schedule_wait_msc;
-        dri2_info.numDrivers = 1;
+        dri2_info.numDrivers = RADEON_ARRAY_SIZE(driverNames);
         dri2_info.driverNames = driverNames;
-        driverNames[0] = dri2_info.driverName;
+        driverNames[0] = driverNames[1] = dri2_info.driverName;
 
 	if (pRADEONEnt->dri2_info_cnt == 0) {
 #if HAS_DIXREGISTERPRIVATEKEY