usb: cdns3: imx: Rework system PM to avoid duplicated operations

The current implementation uses the same callbacks for system PM and
runtime PM suspend/resume without any state checking. This can cause the
clocks to be prepared/unprepared twice, leading to kernel warning issues.

This patch resolves the double prepare/unprepare issues by separating the
runtime PM and system PM handling.

Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Link: https://lore.kernel.org/r/20230523184412.204582-1-shenwei.wang@nxp.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>