kms/crtc: Complain and bail if DRM mode info isn't valid
requested to merge daenzer/mutter:meta_kms_crtc_update_shortterm_max_dispatch_duration-is_drm_mode_valid into main
Otherwise meta_calculate_drm_mode_refresh_rate returns 0.0, which results in non-sense refresh_interval_us.
!3982 (merged) fixed that happening before. This is intended to catch if it ever happens again.
Edited by Michel Dänzer