atmel_spi: label GPIOs better

Make the atmel_spi driver label GPIOs according to the device for which
they're acting as a chipselect.  This way the debugfs dump of gpio state is
more informative.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/spi/atmel_spi.c

@@ -497,7 +497,7 @@ static int atmel_spi_setup(struct spi_device *spi)
 	/* chipselect must have been muxed as GPIO (e.g. in board setup) */
 	npcs_pin = (unsigned int)spi->controller_data;
 	if (!spi->controller_state) {
-		ret = gpio_request(npcs_pin, "spi_npcs");
+		ret = gpio_request(npcs_pin, spi->dev.bus_id);
 		if (ret)
 			return ret;
 		spi->controller_state = (void *)npcs_pin;