perf/x86/intel/uncore: Fix Skylake server PCU PMU event format

perf/x86/intel/uncore: Fix Skylake server PCU PMU event format

PCU event format for SKX are different from snbep. Introduce a new
format group for SKX PCU.

Signed-off-by: Kan Liang <kan.liang@intel.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1499967350-10385-3-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>