platform/x86: intel_pmc_core: Add ICL platform support

Icelake can resue most of the CNL PCH IPs as they are mostly similar.
This patch enables the PMC Core driver for ICL family.

It also addresses few other minor issues like upper case conversions and
some tab alignments.

Cc: "David E. Box" <david.e.box@intel.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-and-tested-by: Anshuman Gupta <anshuman.gupta@intel.com>
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>