[ACPI] IA64 ZX1 buildfix for _PDC patch

http://bugzilla.kernel.org/show_bug.cgi?id=5483



ZX1 config doesn't include cpufreq, so move move acpi-processor.c
up out of ia64/cpufreq directory.

no functional changes

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>