fpga-manager: altera-ps-spi: preserve nCONFIG state

If the driver module is loaded when FPGA is configured, the FPGA
is reset because nconfig is pulled low (low-active gpio inited
with GPIOD_OUT_HIGH activates the signal which means setting its
value to low). Init nconfig with GPIOD_OUT_LOW to prevent this.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Alan Tull <atull@kernel.org>
Signed-off-by: Moritz Fischer <mdf@kernel.org>
Cc: stable <stable@vger.kernel.org> # 4.14+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/fpga/altera-ps-spi.c

@@ -249,7 +249,7 @@ static int altera_ps_probe(struct spi_device *spi)
 
 	conf->data = of_id->data;
 	conf->spi = spi;
-	conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_HIGH);
+	conf->config = devm_gpiod_get(&spi->dev, "nconfig", GPIOD_OUT_LOW);
 	if (IS_ERR(conf->config)) {
 		dev_err(&spi->dev, "Failed to get config gpio: %ld\n",
 			PTR_ERR(conf->config));