acpi: numa: Add genport target allocation to the HMAT parsing

Add SRAT parsing for the HMAT init in order to collect the device handle
from the Generic Port Affinity Structure. The device handle will serve as
the key to search for target data.

Consolidate the common code with alloc_memory_target() in a helper function
alloc_target().

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/170319616951.2212653.14862375982250406464.stgit@djiang5-mobl3


Signed-off-by: Dan Williams <dan.j.williams@intel.com>