hal: reset echo reference at the end of recording/VoIP sessions

Echo reference is not being reset currently at the end of
recording/VoIP session causing the echo reference not to
work in the further instances of recording/VoIP sessions.
Fix this by resetting echo reference while closing the input
stream used for recording/VoIP usecases.

CRs-Fixed: 717973
Change-Id: I761ba112952951777525b1bf102c9d6ccaad3269
hal: ensure EC reference is disabled before enabling

HW echo cancellation is not working after device switch due
to state mismatch between tinyalsa and the kernel.
Ensure that EC reference is disabled always before enabling
EC reference for the new device.

CRs-Fixed: 717973
Change-Id: Ia1152402990db836d3f94278a7d36726310dc60c
Merge "hal: reset echo reference at the end of recording/VoIP sessions"
Merge "hal: ensure EC reference is disabled before enabling"