alpha: Switch to GENERIC_CLOCKEVENTS

This allows us to get rid of some hacky code for SMP.  Get rid of
some cycle counter hackery that's now handled by generic code via
clocksource + clock_event_device objects.

Signed-off-by: Richard Henderson <rth@twiddle.net>

diff --cc arch/alpha/Kconfig
Simple merge

diff --cc arch/alpha/kernel/irq_alpha.c
Simple merge

diff --cc arch/alpha/kernel/proto.h
Simple merge

diff --cc arch/alpha/kernel/smp.c
Simple merge

diff --cc arch/alpha/kernel/time.c
Simple merge