drm/meson: Use drm_module_platform_driver() to register the driver

The macro calls to a DRM specific platform driver init handler that checks
whether the driver is allowed to be registered or not.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211217003752.3946210-13-javierm@redhat.com