x86/apic/32: Remove bigsmp_cpu_present_to_apicid()

It's a copy of default_cpu_present_to_apicid() with the omission of the
actual check whether the CPU is present.

This APIC callback should die completely, but the XEN APIC implementation
does something different which needs to be addressed first.

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)