platform/x86: intel_pmc_core: Quirk to ignore XTAL shutdown

On some platforms such as HP Elite-x2-1013-g3, the platform BIOS
enforces XTAL to remain off before S0ix state can be achieved. This may
not be optimum when we want to enable use cases like Low Power Audio,
Wake on Voice etc which always need 24mhz clock.

This introduces a new quirk to allow S0ix entry when all other
conditions except for XTAL clock are good on a given platform. The extra
power consumed by XTAL clock is about 2mw but it saves much more
platform power compared to the system that remains in just PC10.

Link: https://bit.ly/2UmnrFf
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201579


Tested-by: "David E. Box" <david.e.box@linux.intel.com>
Reported-and-tested-by: russianneuromancer <russianneuromancer@ya.ru>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>