PCI/ASPM: Disable only ASPM_STATE_L1 when driver disables L1

Previously pci_disable_link_state(PCIE_LINK_STATE_L1) disabled L1SS as well
as L1.  This is unnecessary since pcie_config_aspm_link() takes care that
L1SS is not enabled if L1 is disabled.

Disable only ASPM_STATE_L1 when the caller disables L1.  No functional
changes intended.

This is consistent with aspm_attr_store_common(), which disables only L1,
not L1SS, when L1 is disabled via the sysfs "l1_aspm" file.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20230504111301.229358-2-ajayagarwal@google.com


Signed-off-by: Ajay Agarwal <ajayagarwal@google.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>