asoc: bolero: Update PCM_RATE based delay for amic

The PCM_RATE bit field in LPASS_TX_CDC_TXn_TX_PATH_CTL
ranges from 0 to 6.
In the current implementation of tx-macro, the value
read is mapped directly to the sample rate instead of
the indices. Change is to correct this.
Add the delay based on pcm_rate in va-macro as well.

Change-Id: I6cb7e58e71f2a25356608611f1dfed83171706f6
Signed-off-by: Soumya Managoli <smanag@codeaurora.org>