ACPI: Make acpi_dev_get_resources() method agnostic

The function acpi_dev_get_resources() is completely generic and
can be used to parse resource objects that are not necessarily
coming from the _CRS method but also from other objects eg _DMA
that have the same _CRS resource format.

Create an acpi_dev_get_resources() helper, internal to the ACPI
resources parsing compilation unit, __acpi_dev_get_resources(),
that takes a const char* parameter to detect which ACPI method should be
called to retrieve the resources list and make acpi_dev_get_resources()
call it with a method name _CRS leaving the API behaviour unchanged.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>