drm/radeon/dp: Set EDP_CONFIGURATION_SET for bridge chips if necessary

Don't restrict it to just eDP panels.  Some LVDS bridge chips require
this.  Fixes blank panels on resume on certain laptops.  Noticed
by mrnuke on IRC.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=42960



Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org