Moves struct drm_device.hose into struct radeon_device. The field in
struct DRM device is only for legacy drivers.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210112081035.6882-6-tzimmermann@suse.de