ASoC: msm: qdsp6v2: Reset the calibration index

Proxy port is used in audio usecases like wifi display, usb headset
playback.Memory map handle for proxy port was not cached  since the
calibration index was not cleared after DSP responded to calibration
memory map command which resulted in audio mute for wifi display/usb
headset playback usecases.
Change clears the calibration index once a response for calibration
memory map is received.This change will ensure that proxy port memory map
handle is cached which resolves the audio mute issue.

CRs-fixed: 669389
Change-Id: I43c76d472daa9e539168f198969be36af5a0a10c
Signed-off-by: Gopikrishnaiah Anandan <agopik@codeaurora.org>