UBUNTU: SAUCE: PCI/ASPM: Save/restore L1SS Capability for suspend/resume

UBUNTU: SAUCE: PCI/ASPM: Save/restore L1SS Capability for suspend/resume

BugLink: https://bugs.launchpad.net/bugs/1980829
Previously ASPM L1 Substates control registers (CTL1 and CTL2) weren't
saved and restored during suspend/resume leading to L1 Substates
configuration being lost post-resume.

Save the L1 Substates control registers so that the configuration is
retained post-resume.

Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Tested-by: Abhishek Sahu <abhsahu@nvidia.com>
(cherry picked from commit https://patchwork.ozlabs.org/project/linux-pci/patch/20220705060014.10050-1-vidyas@nvidia.com/)
Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Aaron Ma <aaron.ma@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>