drm/vmwgfx: Limit max desktop dimensions to 8Kx8K

This was originally chosen to be an arbitrarily large number.  However,
some user mode may actually try to set a 16Kx16K mode and run into other
issues.

Since 8Kx8K is the current texture limit for Mesa LLVM driver, we will
just use this limit for now.

Cc: <stable@vger.kernel.org> # 4.12.x
Signed-off-by: Sinclair Yeh <syeh@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c

@@ -1640,8 +1640,8 @@ int vmw_kms_stdu_init_display(struct vmw_private *dev_priv)
 		 * something arbitrarily large and we will reject any layout
 		 * that doesn't fit prim_bb_mem later
 		 */
-		dev->mode_config.max_width = 16384;
-		dev->mode_config.max_height = 16384;
+		dev->mode_config.max_width = 8192;
+		dev->mode_config.max_height = 8192;
 	}
 
 	vmw_kms_create_implicit_placement_property(dev_priv, false);