ENGR00178612 ESAI:add support for esai call asrc

ENGR00178612 ESAI:add support for esai call asrc

ESAI can call ASRC for sample rate convert if the input sample rate
is not support.
1 ESAI will decide whether to use ASRC for sample rate convert in
  imx-cs42888.c. If ASRC is need, the asrc_enable will be set.
2 In imx-pcm-dma-mx2.c, according to the value of asrc_enable, the
  dma driver would decide whether to alloc another p2p dma channel to
  support MEMORY-->ASRC_INPUT-->ASRC_OUTPUT-->ESAI_TX_FIFO route.
3 The code support 2 channel,24/32 bit audio file playback.

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