sparc64: T5 PMU

The T5 (niagara5) has different PCR related HV fast trap values and a new
HV API Group. This patch utilizes these and shares when possible with niagara4.

We use the same sparc_pmu niagara4_pmu. Should there be new effort to
obtain the MCU perf statistics then this would have to be changed.

Cc: sparclinux@vger.kernel.org
Signed-off-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>