spi: gpio: Look for a device node instead of match

This driver doesn't do anything with the match for the device node. The
logic is the same as looking to see if a device node exists or not
because this driver wouldn't probe unless there is a device node match
when the device is created from DT. Just test for the presence of the
device node to simplify and avoid referencing a potentially undefined
match table when CONFIG_OF=n.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: <linux-spi@vger.kernel.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20191004214334.149976-9-swboyd@chromium.orgSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-gpio.c

@@ -362,9 +362,6 @@ static int spi_gpio_probe(struct platform_device *pdev)
 	struct spi_gpio			*spi_gpio;
 	struct device			*dev = &pdev->dev;
 	struct spi_bitbang		*bb;
-	const struct of_device_id	*of_id;
-
-	of_id = of_match_device(spi_gpio_dt_ids, &pdev->dev);
 
 	master = spi_alloc_master(dev, sizeof(*spi_gpio));
 	if (!master)
@@ -374,7 +371,7 @@ static int spi_gpio_probe(struct platform_device *pdev)
 	if (status)
 		return status;
 
-	if (of_id)
+	if (pdev->dev.of_node)
 		status = spi_gpio_probe_dt(pdev, master);
 	else
 		status = spi_gpio_probe_pdata(pdev, master);