perf/x86: Dump DEBUGCTL in PMU dump

LBRs and LBR freezing are controlled through the DEBUGCTL MSR. So
dump the state of DEBUGCTL too when dumping the PMU state.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1425059312-18217-3-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>