drm/sitronix: move tiny Sitronix drivers to their own subdir

We start to have support many Sitronix displays in the tiny directory,
and we expect more to come.

Move them to their own subdirectory.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Suggested-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250512-sitronix-v3-1-bbf6cc413698@gmail.com


Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>