Bug#1106548: digimend-dkms: module fails to build for Linux 6.15: implicit declaration of function 'del_timer_sync'

[Kentaro HAYASHI]

NOTE: someone already working on PR.

  fix: Rename del_timer_sync() to timer_delete_sync()
  https://github.com/DIGImend/digimend-kernel-drivers/pull/714

Regards,