freedreno: fix crash on smaller gpus and higher resolutions

Devices with smaller GMEM size need more tiles.  On db410c at 2048x1152,
glmark2 shadow needed ~330 tiles for fullscreen.  Lets bump it up to
512.  (Maybe with MRT you could end up needing more, but at that point
things are probably going to be painfully slow.)

Signed-off-by: Rob Clark <robdclark@gmail.com>

src/gallium/drivers/freedreno/freedreno_context.h

@@ -316,7 +316,7 @@ struct fd_context {
 	 */
 	struct fd_gmem_stateobj gmem;
 	struct fd_vsc_pipe      pipe[8];
-	struct fd_tile          tile[256];
+	struct fd_tile          tile[512];
 
 	/* which state objects need to be re-emit'd: */
 	enum {