drm/amd/pm: Restore config space after reset

During mode-2 reset, pci config space registers are affected at device
side. However, certain platforms have switches which assign virtual BAR
addresses and returns the same even after device is reset. This
affects pci_restore_state() as it doesn't issue another config write, if
the value read is same as the saved value.

Add a workaround to write saved config space values from driver side.
Presently, these switches are in platforms with SMU v13.0.6 SOCs, hence
restrict the workaround only to those.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Asad Kamal <asad.kamal@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>