panic_handle: Save kernel msg into EMMC when kernel panic FOR NEW OPTION

panic_handle: Save kernel msg into EMMC when kernel panic FOR NEW OPTION

BZ: 17212

Adding a new option for enabling the emmc panic handler

Change-Id: I2838e2e7291ca46c4525f3d7b63ef9371a4c8d53
Signed-off-by: liu chuansheng <chuansheng.liu@intel.com>
Reviewed-on: http://android.intel.com:8080/26993
Reviewed-by: Guerard, Christophe <christophe.guerard@intel.com>
Tested-by: Zhang, Dongxing <dongxing.zhang@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>