x86, apic: Remove multi_timer_check callback

Since commit b5660ba7 ("x86, platforms: Remove NUMAQ") removed NUMAQ,
the multi_timer_check() apic callback has been obsolete.  Remove it.

Signed-off-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1407302351120.17503@chino.kir.corp.google.com


Signed-off-by: H. Peter Anvin <hpa@zytor.com>