hardware/samsung: Remove -lpthread from RIL makefiles

Change-Id: Ib0893101196519790fa21ad47e0524ebec479d87

Conflicts:
	ril/libsecril-client-sap/Android.mk
	ril/libsecril-client/Android.mk
	ril/xmm6260/libril/Android.mk
	ril/xmm6262/libril/Android.mk