spi: sirf: make GPIO chipselect function work well

orignal GPIO chipslect is not standard because it don't take care to the
chipselect signal: BITBANG_CS_ACTIVE and BITBANG_CS_INACTIVE.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/spi-sirf.c

@@ -470,7 +470,16 @@ static void spi_sirfsoc_chipselect(struct spi_device *spi, int value)
 		writel(regval, sspi->base + SIRFSOC_SPI_CTRL);
 	} else {
 		int gpio = sspi->chipselect[spi->chip_select];
-		gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
+		switch (value) {
+		case BITBANG_CS_ACTIVE:
+			gpio_direction_output(gpio,
+					spi->mode & SPI_CS_HIGH ? 1 : 0);
+			break;
+		case BITBANG_CS_INACTIVE:
+			gpio_direction_output(gpio,
+					spi->mode & SPI_CS_HIGH ? 0 : 1);
+			break;
+		}
 	}
 }