Update to EGL_MESA_drm_image from mesa master

Woo, running on stock mesa now.
diff --git a/clients/window.c b/clients/window.c
index a56bcfa..2b88e09 100644
--- a/clients/window.c
+++ b/clients/window.c
@@ -246,8 +246,8 @@
 	EGLint image_attribs[] = {
 		EGL_WIDTH,		0,
 		EGL_HEIGHT,		0,
-		EGL_IMAGE_FORMAT_MESA,	EGL_IMAGE_FORMAT_ARGB8888_MESA,
-		EGL_IMAGE_USE_MESA,	EGL_IMAGE_USE_SCANOUT_MESA,
+		EGL_DRM_BUFFER_FORMAT_MESA,	EGL_DRM_BUFFER_FORMAT_ARGB32_MESA,
+		EGL_DRM_BUFFER_USE_MESA,	EGL_DRM_BUFFER_USE_SCANOUT_MESA,
 		EGL_NONE
 	};