Move the cursor code into a separate source file for readability. No
functional changes.

v2:
- include <linux/bits.h>

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250217122336.230067-5-tzimmermann@suse.de