usb: chipidea: usbmisc: add power lost check for imx6sx

imx6sx mega off can shutdown domain power supply if none of peripheral
in this domain is registered as wakeup source, this patch add related
codes to check if power is lost.

Signed-off-by: Li Jun <jun.li@nxp.com>
Link: https://lore.kernel.org/r/20221013151442.3262951-7-xu.yang_2@nxp.com


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