spi: fsl-dspi: several minor improvements and fixes

 - improve dependencies using COMPILE_TEST
 - fix a typo
 - drop platform_set_drvdata(pdev, NULL) in error path of probe
 - make MODULE_LICENSE match the header

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index b9c53cc..c463d36 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -264,6 +264,7 @@
 config SPI_FSL_DSPI
 	tristate "Freescale DSPI controller"
 	select SPI_BITBANG
+	depends on SOC_VF610 || COMPILE_TEST
 	help
 	  This enables support for the Freescale DSPI controller in master
 	  mode. VF610 platform uses the controller.