drm/radeon: fix panel scaling with eDP and LVDS bridges
drm/radeon: fix panel scaling with eDP and LVDS bridges

From Alex Deucher
1746ed29ec8fded44bd8fbc96fe8cd72f55d3031 in ubuntu 3.8
855f5f1d882a34e4e9dd27b299737cd3508a5624 in mainline linux

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars