ENGR00238439 ASRC: add delay before reading ASRC FIFO status

ENGR00238439 ASRC: add delay before reading ASRC FIFO status

ASRC driver would read the sample number of ASRC output FIFO to fetch
the data from ASRC output FIFO. However, SDMA's fetching operation may
not finished before ASRC's reading. In this case, ASRC driver may read a
error data from the register.

In this patch, add delay before reading ASRC FIFO status to prevent
noise.

Signed-off-by: Chen Liangjun <b36089@freescale.com>