radio: iris: Fix the issue with hard mute IOCTL

- Hard mute IOCTL is setting the soft mute as well irrespective
  whether it is required or not.
- Setting only hard mute.

Change-Id: Ifb2c91f4bb1f1c3418c65c57fccd65c7656170c0
CRs-Fixed: 656715
Signed-off-by: Venkateshwarlu Domakonda <vdomak@codeaurora.org>