[PORT FROM R2]pti: Check if pti is enabled in mipi header

[PORT FROM R2]pti: Check if pti is enabled in mipi header

BZ: 28818

Check in init if pti is enabled in mipi header. In case of pti is
disabled return error to avoid further accesses on pti.

Return NULL from pti_request_masterchannel if init have failed due to
disabled pti or some other error.

Change-Id: I3944c2e22b4bbe3f99b11763fb3f63c83da1b39a
Signed-off-by: Jouni Hogander <jouni.hogander@intel.com>
Reviewed-on: http://android.intel.com:8080/46039
Reviewed-by: Skowronski, Philippe <philippe.skowronski@intel.com>
Reviewed-by: Koskinen, Ilkka <ilkka.koskinen@intel.com>
Reviewed-by: Guerard, Christophe <christophe.guerard@intel.com>
Tested-by: Guerard, Christophe <christophe.guerard@intel.com>
Reviewed-by: Lebouc, Christophe <christophe.lebouc@intel.com>
Tested-by: Lebouc, Christophe <christophe.lebouc@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>