m7-common: Add low latency audio usecases

Change-Id: Ibd91e286d8b05d3aba65f2e8edebeb291297a9e4

Conflicts:
	dsp/snd_soc_msm/snd_soc_msm_2x_Fusion3

(renumbered 40 to 41 to match our kernel)
audio_policy: enable low latency audio

Change-Id: I086c3b9b89ea6074f1b83e30ec9a22493ce38335