platform/x86: intel_pmc_core: Clean up: Remove comma after the termination line

It is common practice to place a comma after the last entry in an
initialized array to avoid the need to add one in future patches that
extend the array. But when the last element is a termination marker, the
comma could be harmful. Any new entries must be added before the
terminator (and the comma would prevent the compiler from issuing a
warning about an entry after the terminator).

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: David E. Box <david.e.box@intel.com>
Cc: Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>
Cc: Tony Luck <tony.luck@intel.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Gayatri Kammela <gayatri.kammela@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>