The Speaker GPIO needs to be turned on slightly behind the codec turned on.
It also need to be turned off slightly before the codec turned down.
Current code uses delay in DAPM_EVENT to do it but the mdelay delays the
DAPM itself and thus has no effect. A delayed_work is added to turn on the
speaker.
The Speaker is turned off in .trigger since trigger is called slightly
before the DAPM events.
Signed-off-by: Zhu Ning <zhuning@everest-semi.com>

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v1: cancel delayed work while disabling speaker.
Link: https://lore.kernel.org/r/20221028020456.90286-1-zhuning0077@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>