BugLink: http://bugs.launchpad.net/bugs/1559349

ARMv8.1 increases the PMU event number space to 16 bit so increase
the EVTYPE mask.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from linux-next commit c210ae80)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>