spi: imx: Fix failure path leak on GPIO request error

If the code that requests any chip select GPIOs fails, the cleanup of
spi_bitbang_start() by calling spi_bitbang_stop() is not done.  Add this
to the failure path.

Note that spi_bitbang_start() has to be called before requesting GPIOs
because the GPIO data in the spi master is populated when the master is
registed, and that doesn't happen until spi_bitbang_start() is called.

CC: Shawn Guo <shawnguo@kernel.org>
CC: Sascha Hauer <kernel@pengutronix.de>
CC: Fabio Estevam <fabio.estevam@nxp.com>
CC: Mark Brown <broonie@kernel.org>
CC: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Trent Piepho <tpiepho@impinj.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-imx.c

@@ -1633,7 +1633,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 			if (ret) {
 				dev_err(&pdev->dev, "Can't get CS GPIO %i\n",
 					master->cs_gpios[i]);
-				goto out_clk_put;
+				goto out_spi_bitbang;
 			}
 		}
 	}
@@ -1650,6 +1650,8 @@ static int spi_imx_probe(struct platform_device *pdev)
 	clk_disable(spi_imx->clk_per);
 	return ret;
 
+out_spi_bitbang:
+	spi_bitbang_stop(&spi_imx->bitbang);
 out_clk_put:
 	clk_disable_unprepare(spi_imx->clk_ipg);
 out_put_per: