del_timer_sync is undefined

[InterLinked1]

Kernel commit torvalds/linux@8fa7292 removed the wrapper for del_timer_sync, which now causes compilation to fail on kernels >= 6.15:

wctc4xxp/base.c: In function 'wctc4xxp_remove_one':
wctc4xxp/base.c:4168:13: error: implicit declaration of function 'del_timer_sync'; did you mean 'dev_mc_sync'? [-Werror=implicit-function-declaration]
 4168 |         if (del_timer_sync(&wc->watchdog))
      |             ^~~~~~~~~~~~~~
      |             dev_mc_sync
cc1: all warnings being treated as errors
make[5]: *** [/usr/src/linux/scripts/Makefile.build:203: wctc4xxp/base.o] Error 1
make[4]: *** [/usr/src/linux/scripts/Makefile.build:461: wctc4xxp] Error 2
make[3]: *** [/usr/src/linux/Makefile:2003: .] Error 2
make[2]: *** [/usr/src/linux/Makefile:248: __sub-make] Error 2
make[2]: Leaving directory '/usr/src/dahdi-linux-3.4.0/drivers/dahdi'
make[1]: *** [Makefile:248: __sub-make] Error 2
make[1]: Leaving directory '/usr/src/linux'
make: *** [Makefile:74: modules] Error 2