ASoC: qdsp6v2: Clear memory map handle during ADSP SSR

AFE topology information is not shown in real time audio calibration
tool(RTAC) after ADSP subsystem restart because memory map handle is
not reset. Set/get param APIs fail because of this stale memory map
handle. Fix this issue by clearing AFE memory map handle during SSR.

Change-Id: Id8b1fad6580c11ba504e8781643f3d0f584eae7b
Signed-off-by: Vidyakumar Athota <vathota@codeaurora.org>