ACPI: remove unused have_arch_parse_srat

This was a workaround for 32bit numa SRAT processing, and we removed those
workarounds, making 32 bit more like 64 bit.  HAVE_ARCH_PARSE_SRAT is no
longer defined anywhere.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>