[nrf fromlist] drivers: nrf_wifi: Fix the interoperability issues

With few APs we have seen unexplained disconnections and sending
keepalive often solves the problem, so, to fix interoperability reduce
the keepalive period to 30s.

Upstream PR #: 93920

Signed-off-by: Chaitanya Tata <Chaitanya.Tata@nordicsemi.no>

Author: krish2718

drivers/wifi/nrf_wifi/Kconfig.nrfwifi

@@ -840,7 +840,7 @@ if NRF_WIFI_FEAT_KEEPALIVE
 config NRF_WIFI_KEEPALIVE_PERIOD_S
 	int "Keepalive period in seconds"
 	range 30 3600
-	default 60
+	default 30
 	help
 	  Keepalive period in seconds to send keepalive packets to the AP.
 endif