google/rush_ryu: devicetree: Add framebuffer resolution settings

When displaying a 800x600 bitmap on 2560x1800 panel, the image
is shown very small. So, set the fb to 1280x800 (based on tegra
dsi driver default mode setting), a 800x600 image can be shown
relatively proportional to panel size.

BRANCH=none
BUG=chrome-os-partner:31936
TEST=build and test on ryu

Signed-off-by: Jimmy Zhang <jimmzhang@nvidia.com>

Change-Id: I1e360aeaec97b9df5d86e46951ab1326610260d2
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 67c2a381322721a24b1b7f9ac366073b7e3c490c
Original-Change-Id: I62cbe9de1d1002293df20f8b1d752905c6ef33aa
Original-Reviewed-on: https://chromium-review.googlesource.com/229912
Original-Tested-by: Jimmy Zhang <jimmzhang@nvidia.com>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/9521
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/mainboard/google/rush_ryu/devicetree.cb b/src/mainboard/google/rush_ryu/devicetree.cb
index c0af141..b5c99819 100644
--- a/src/mainboard/google/rush_ryu/devicetree.cb
+++ b/src/mainboard/google/rush_ryu/devicetree.cb
@@ -33,6 +33,10 @@
 	register "framebuffer_bits_per_pixel" = "32"
 	register "color_depth" = "12"
 
+	# framebuffer resolution
+	register "display_xres" = "1280"
+	register "display_yres" = "800"
+
 	register "href_to_sync" = "1"
 	register "hfront_porch" = "80"
 	register "hsync_width" = "80"