Revert "g3: split mixer_paths for bcm/wcnss"

This reverts commit 205b4c4078bce0402945fb6a81ef58d2892245df.

	renamed:    configs/mixer_paths_bcm.xml -> configs/mixer_paths.xml
	deleted:    configs/mixer_paths_qcwcn.xml
	modified:   g3.mk
	modified:   BoardConfigCommon.mk
g3: split mixer_paths for bcm/wcnss

Change-Id: Ic29f8420297f55091736d04cb4dece30ac6cbe4c