posix-timers: Convert timer_create() to clockid_to_kclock()

Setup timer_create for CLOCK_MONOTONIC and CLOCK_REALTIME kclocks and
remove the no_timer_create() implementation.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: John Stultz <johnstul@us.ibm.com>
Tested-by: Richard Cochran <richard.cochran@omicron.at>
LKML-Reference: <20110201134418.903604289@linutronix.de>