wifi: ath11k: Use RMW accessors for changing LNKCTL

wifi: ath11k: Use RMW accessors for changing LNKCTL

Don't assume that only the driver would be accessing LNKCTL. ASPM policy
changes can trigger write to LNKCTL outside of driver's control.

Use RMW capability accessors which do proper locking to avoid losing
concurrent updates to the register value. On restore, clear the ASPMC field
properly.

Suggested-by: Lukas Wunner <lukas@wunner.de>
Fixes: e9603f4bdcc0 ("ath11k: pci: disable ASPM L0sLs before downloading firmware")
Link: https://lore.kernel.org/r/20230717120503.15276-9-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Kalle Valo <kvalo@kernel.org>