posix-clock: Remove duplicate compat ioctl() handler

The normal and compat ioctl handlers are identical,
which is fine as compat ioctls are detected and handled dynamically
inside the underlying clock implementation.
The duplicate definition however is unnecessary.

Just reuse the regular ioctl handler also for compat ioctls.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Link: https://lore.kernel.org/all/20250225-posix-clock-compat-cleanup-v2-1-30de86457a2b@weissschuh.net