ASoC: fsl: Replace tasklet with work

The tasklet is an old API that should be deprecated, usually can be
converted to another decent API.  In ASoC FSL ESAI CPU DAI driver, a
tasklet is still used for offloading the hardware reset function.
It can be achieved gracefully with a work queued, too.

This patch replaces the tasklet usage in fsl esai driver with a simple
work.  The conversion is fairly straightforward.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20200903104749.21435-2-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>