drivers: wifi: Update RPU patch to release/v2.6 rev#3fc62454e39

UMAC: Fixes from v2.5 branch
      1) Added watchdog timer programming from Host.
      2) Handling TRIGGER_SWITCH_PS from LMAC.
      3) Clearing and re-enabling watchdog before sending any
         event from UMAC to Host.
      4) [SHEL-2995] : Parsing keep alive parameters from host in command
                       init and sending to LMAC.

LMAC: Fixes/features from 2.5 branch
      1) Keep alive logic
      2) Null frame based power save
      3) TSF sync

Signed-off-by: Karun Kumar Eagalapati <[email protected]>

nrf_wifi/fw_if/umac_if/inc/fw/host_rpu_sys_if.h

@@ -828,6 +828,17 @@ enum op_band {
 	BAND_24G
 };
 
+/**
+ * @brief This enum defines keep alive state
+ *
+ */
+enum keep_alive_status {
+	/** Keep alive feature disabled */
+	KEEP_ALIVE_DISABLED = 0,
+	/** Keep alive feature enabled */
+	KEEP_ALIVE_ENABLED = 1
+};
+
 /**
  * @brief This enum specifies the type of frames used to retrieve buffered data
  *  from the AP in power save mode.
@@ -889,6 +900,16 @@ struct nrf_wifi_cmd_sys_init {
 	 * from the AP in power save @ref data_retrieve_mechanism.
 	 */
 	unsigned char ps_data_retrieval_mech;
+	/** The RPU uses this value to configure watchdog timer */
+	unsigned int watchdog_timer_val;
+	/** The RPU uses this value to decide whether keep alive
+	 *  feature is enabled or not see enum keep_alive_status
+	 */
+	unsigned char keep_alive_enable;
+	/** The RPU uses this value(in seconds) for periodicity of the keep
+	 *  alive frame.
+	 */
+	unsigned int keep_alive_period;
 } __NRF_WIFI_PKD;
 
 /**