Cores need to be included into the debug mask. We don't exactly
know what it does but the spec says it must be enabled. So obey.

v2: Cores should be only set for BXT (Imre, Art)

Cc: Imre Deak <imre.deak@intel.com>
Cc: Runyan, Arthur J <arthur.j.runyan@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1455877564-5128-1-git-send-email-mika.kuoppala@intel.com