s32-gen1: pcie: Fix STR when NVME SSD is mounted in rootfs

commit ccf0ff55211911cfa512e2c40b94e1d043a04e04 from
https://source.codeaurora.org/external/autobsps32/linux



In 'suspend' routine, we mark any EP devices as disconnected,
before attempting to stop & remove those EP devices.

Issue: ALB-8263
Signed-off-by: Ciprian Costea <ciprianmarian.costea@nxp.com>
Signed-off-by: Zhantao Tang <zhantao.tang@windriver.com>