Audio: Revert hal changes to block pcm_close during SSR

 pcm driver supports pcm_close during SSR, so reverted
 HAL code to block pcm session close during SSR.

 CRs-Fixed: 663477

Change-Id: I752e3f4f55288f91294e090b974ba1367c27122d
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_hardware_qcom_audio-caf into HEAD