ril: Avoid collision with RIL constant 1138

used in some Samsung devices for RIL_UNSOL_TETHERED_MODE_STATE_CHANGED.

 Thanks to iptux on XDA for pointing out the change in constants between
 CM-10.2 and CM-11.0.

 This patch is complimentary to:
 http://review.cyanogenmod.org/#/c/61289/

Conflicts:
	libril/telephony/ril.h