backends/drm: better format checking
Commit 1: ensure correct format+modifiers pairs for surfaces by checking if the format is supported and the modifier list is the same
Commit 2: Remove the check for GPU-wide supported formats. As formats are per output and also checked on crtc changes now, there is no reason to restrict used formats to those that are supported by all primary planes anymore.
Without commit 1, super weird hardware could have outputs potentially failing in rare corner cases.