msm: audio: qdsp6v2: remove unmap ion region before disable

In the use case of audio playback in non tunnel mode, in audio release
unmap is called twice, before and after audio disable. This is
resulting to request DSP to unmap the region twice. Remove the unmap of
the ion region before audio disable.

CRs-Fixed: 443535

Change-Id: Iba44647063c85ab48091888ab5a583b6208dbb3e
Signed-off-by: Subhash Chandra Bose Naripeddy <snariped@codeaurora.org>