kernel: enable CONFIG_RFKILL.

kernel: enable CONFIG_RFKILL.

BZ: 15061

Enable full control of the Radio from the user space. Feature required
by some wifi applications.

Change-Id: Ic9e5276e84f2a30e4f7f1abc7c1b71b646b06127
Signed-off-by: Aymen Zayet <aymenx.zayet@intel.com>
Reviewed-on: http://android.intel.com:8080/25382
Reviewed-by: Champciaux, NicolasX <nicolasx.champciaux@intel.com>
Tested-by: Champciaux, NicolasX <nicolasx.champciaux@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>