ASoC: Intel: Skylake: Disable SRAM Retention before D3

SW needs to set the PGCTL.LSRMD = 1 to disable LPSRAM retention
feature,otherwise it may lead to SRAM ECC Errors.

Signed-off-by: Dharageswari R <dharageswari.r@intel.com>
Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/sound/soc/intel/skylake/skl.c b/sound/soc/intel/skylake/skl.c
index 55c301b..cb3eb41 100644
--- a/sound/soc/intel/skylake/skl.c
+++ b/sound/soc/intel/skylake/skl.c
@@ -186,6 +186,7 @@
 {
 	struct skl *skl = ebus_to_skl(ebus);
 	struct hdac_bus *bus = ebus_to_hbus(ebus);
+	struct pci_dev *pci = to_pci_dev(bus->dev);
 	int ret;
 
 	snd_hdac_ext_bus_link_power_down_all(ebus);
@@ -195,6 +196,8 @@
 		return ret;
 
 	snd_hdac_bus_stop_chip(bus);
+	update_pci_dword(pci, AZX_PCIREG_PGCTL,
+		AZX_PGCTL_LSRMD_MASK, AZX_PGCTL_LSRMD_MASK);
 	skl_enable_miscbdcge(bus->dev, false);
 	snd_hdac_bus_enter_link_reset(bus);
 	skl_enable_miscbdcge(bus->dev, true);