In order to correctly pause audio on suspend, amps using external boost
require parts of the pause sequence to be called for all amps before moving
on to the next steps.
For example, as part of pausing the audio, the VSPK GPIO must be disabled,
but since this GPIO is controlled by one amp, but controls the boost for
all amps, it is required to separate the calls.
During playback this is achieved by using the pre and post playback hooks,
however during system suspend, this is not possible, so to separate the
calls, we use both the .prepare and .suspend calls to pause the audio.

Currently, for this reason, we do not restart audio on system resume.
However, we can support this by relying on the playback hook to resume
playback after system suspend.
Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230721151816.2080453-10-sbinding@opensource.cirrus.comSigned-off-by: Takashi Iwai <tiwai@suse.de>