fix target devices

I got this error:
build/core/base_rules.mk:130: *** device/motorola/msm8960-common/modules/camerawrapper: MODULE.TARGET.SHARED_LIBRARIES.camera.msm8960 already defined by device/htc/m7-common/camera.

(It tries to build the moto camera wrapper for the htc m7 too)
This pull request should fix that behaviour..