x86: acpi use cpu_physical_id

This is from an earlier message from Christoph Lameter:

    processor_core.c currently tries to determine the apicid by special casing
    for IA64 and x86. The desired information is readily available via

	    cpu_physical_id()

    on IA64, i386 and x86_64.

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Additionally, boot_cpu_id needed to be exported to fix compile errors in
dma code when !CONFIG_SMP.

Signed-off-by: Mike Travis <travis@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>