rockchip: Add ABGR8888 format.

Chromium expects this format to be supported for import of
foreign buffers.

BUG=chromium:541558
TEST=chromium glimage tests pass

Change-Id: I7ff2f53ef31fc491699f7ad9aea34b3e63289690
Reviewed-on: https://chromium-review.googlesource.com/312591
Commit-Ready: David Reveman <reveman@chromium.org>
Tested-by: David Reveman <reveman@chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
diff --git a/rockchip.c b/rockchip.c
index db17d7c..0a721da 100644
--- a/rockchip.c
+++ b/rockchip.c
@@ -46,6 +46,7 @@
 	.format_list = {
 		{GBM_FORMAT_XRGB8888, GBM_BO_USE_SCANOUT | GBM_BO_USE_CURSOR | GBM_BO_USE_RENDERING | GBM_BO_USE_WRITE},
 		{GBM_FORMAT_ARGB8888, GBM_BO_USE_SCANOUT | GBM_BO_USE_CURSOR | GBM_BO_USE_RENDERING | GBM_BO_USE_WRITE},
+		{GBM_FORMAT_ABGR8888, GBM_BO_USE_SCANOUT | GBM_BO_USE_CURSOR | GBM_BO_USE_RENDERING | GBM_BO_USE_WRITE},
 	}
 };