timer_list: print cpu number of clockevents device

The per cpu clock events device output of timer_list lacks an
association of the device to the cpu which is annoying when looking at
the output of /proc/timer_list from a 128 way system.

Add the CPU number info and mark the broadcast device in the device
list printout.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>