ACPI: Disambiguate processor declaration type

Declaring processors in ACPI namespace can be done using either a
"Processor" definition or a "Device" definition (see section 8.4 -
Declaring Processors; "Advanced Configuration and Power Interface
Specification", Revision 3.0b).  Currently the two processor
declaration types are conflated.

This patch disambiguates the processor declaration's definition type
enabling subsequent code to behave uniquely based explicitly on the
declaration's type.

Signed-off-by: Myron Stowe <myron.stowe@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>