backend/drm: fix modeset on drm fd resume
Created by: RedSoxFan
Fixes #1560 (closed)
On DRM resume, such as switching back to a TTY, the output needs to be modeset to the current mode. However, wlr_output_set_mode will return early when attempting to set the mode to the current mode. This just steps around wlr_output_set_mode and calls drm_connector_set_mode directly.