x86/apic: Nuke apic::apicid_to_cpu_present()

This is only used on 32bit and is a wrapper around
physid_set_mask_of_physid() in all 32bit APIC drivers.

Remove the callback and use physid_set_mask_of_physid() in the code
directly,

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)