dma: mxs-dma: use global stmp_device functionality

This can get rid of the mach-dependency.

Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Huang Shijie <b32955@freescale.com>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Marek Vasut <marex@denx.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index ef378b5..aadeb5b 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -238,6 +238,7 @@
 config MXS_DMA
 	bool "MXS DMA support"
 	depends on SOC_IMX23 || SOC_IMX28
+	select STMP_DEVICE
 	select DMA_ENGINE
 	help
 	  Support the MXS DMA engine. This engine including APBH-DMA