ASoC: fsl_rpmsg: Remove SET_SYSTEM_SLEEP_PM_OPS callback

For sound need to be continuously output at suspend with rpmsg
sound card, so need to keep the clock always on at suspend,
then suspend & resume callback is not needed.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1646822293-26965-1-git-send-email-shengjiu.wang@nxp.com


Signed-off-by: Mark Brown <broonie@kernel.org>