modules: nrf_wifi: Fix interface down hang

When QSPI LPM is enabled, QSPI will already be uninitialized, and during
deinit if uninitialized is being called again then it leads to a hang as
it waits for mem busy check to pass which it won't.

Fix by checking if the device is initialized before calling
uninitialize.

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

Author: krish2718

modules/nrf_wifi/bus/qspi_if.c

@@ -1196,7 +1196,9 @@ struct device qspi_perip = {
 
 int qspi_deinit(void)
 {
-	_qspi_device_uninit(&qspi_perip);
+	if (nrfx_qspi_init_check()) {
+		_qspi_device_uninit(&qspi_perip);
+	}
 
 	return 0;
 }