slim_msm: Reorganise Rx/Tx tear-down during DSP-SSR

Rx/Tx pipe resources are freed during DSP down.
Simultaneously BAM ISR due to Rx/Tx interrupt
may access the Rx/Tx pipe resources leading to
pagingfault.
To overcome this, Rx/Tx activity is reorganised by
disabling the interrupt during ADSP down and
freeing, allocating resources during ADSP up.

Change-Id: Id1b77a05a042ef9ca194f78e700670edf6146db6
Signed-off-by: Dilip Kota <dkota@codeaurora.org>