ASoC: msm: Fix ADM RTAC

When low latency playback feature was added
RTAC devices were added but not removed.
Removed low latency devices completely from
being added and removed from RTAC

Change-Id: If64ccb685dd1bccf734a40ff694c6e95e037b22e
CRs-fixed: 487539
Signed-off-by: Ben Romberger <bromberg@codeaurora.org>