Most modern platforms already have the ACPI device "INT33A1" that could
be used to attach to the driver. Switch the driver to using that and
thus make the intel_pmc_core.c a pure platform_driver.

Some of the legacy platforms though, may still not have this ACPI device
in their ACPI tables. Thus for such platforms, move the code to manually
instantiate a platform_device into a new file of its own. This would
instantiate the intel_pmc_core platform device and thus attach to
the driver, if the ACPI device for the same ("INT33A1") is not present
in a system where it should be. This was discussed here:
https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1966991.htmlSigned-off-by: Rajat Jain <rajatja@google.com>
[andy: renamed to intel_pmc_core_pltdrv.c to be in align with other drivers]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>