Add support for DRM_FORMAT_P010

Test: Tested with chrome's ozone_gl_unittests: crrev.com/c/1561136
Bug: 911754
Change-Id: I8a9a28ba1c3a1186fd88b43c85098a5550fa1c8b
Reviewed-on: https://chromium-review.googlesource.com/1590464
Commit-Ready: Miguel Casas <mcasas@chromium.org>
Tested-by: Miguel Casas <mcasas@chromium.org>
Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
diff --git a/drv.h b/drv.h
index d27e845..d3cf9d3 100644
--- a/drv.h
+++ b/drv.h
@@ -56,6 +56,11 @@
 #define DRM_FORMAT_FLEX_IMPLEMENTATION_DEFINED	fourcc_code('9', '9', '9', '8')
 #define DRM_FORMAT_FLEX_YCbCr_420_888		fourcc_code('9', '9', '9', '9')
 
+// TODO(crbug.com/958181): remove this definition once drm_fourcc.h contains it.
+#ifndef DRM_FORMAT_P010
+#define DRM_FORMAT_P010 fourcc_code('P', '0', '1', '0')
+#endif
+
 // clang-format on
 struct driver;
 struct bo;