cnss2: Add sysfs support for configuring timer sync interval

It can be used to tune the host and fw time synchronization interval
for better accuracy.

Change-Id: I0a3d8895520cec526341f278c91f153dd0bd1966
CRs-Fixed: 3257702

cnss2/pci.h

@@ -279,4 +279,6 @@ int cnss_pci_get_iova_ipa(struct cnss_pci_data *pci_priv, u64 *addr,
 			  u64 *size);
 void cnss_pci_handle_linkdown(struct cnss_pci_data *pci_priv);
 
+int cnss_pci_update_time_sync_period(struct cnss_pci_data *pci_priv,
+				     unsigned int time_sync_period);
 #endif /* _CNSS_PCI_H */