drm/simpledrm: Do not upcast in release helpers

drm/simpledrm: Do not upcast in release helpers

The res pointer passed to simpledrm_device_release_clocks() and
simpledrm_device_release_regulators() points to an instance of
struct simpledrm_device. No need to upcast from struct drm_device.
The upcast is harmless, as DRM device is the first field in struct
simpledrm_device.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 11e8f5fd223b ("drm: Add simpledrm driver")
Cc: <stable@vger.kernel.org> # v5.14+
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250407134753.985925-2-tzimmermann@suse.de