drm/qxl: Move ioctl array next to its only user

Move the array qxl_ioctl to qxl_drv.c and initialize the num_ioctls
field of struct drm_driver at runtime. Replaces the current fragile
ioctl setup and allows for generating the module init/exit code.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211217144615.32733-8-tzimmermann@suse.de