dmaengine: Kconfig: Simplify the help text for MXS_DMA

Currently the help text for the MXS_DMA option is incomplete as it does
not mention MX6SX, MX6ULL and MX7D, for example.

Instead of extending this list everytime a new SoC comes out, let's
keep the text more generic.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

drivers/dma/Kconfig

@@ -359,8 +359,7 @@ config MXS_DMA
 	select DMA_ENGINE
 	help
 	  Support the MXS DMA engine. This engine including APBH-DMA
-	  and APBX-DMA is integrated into Freescale
-	  i.MX23/28/MX6Q/MX6DL/MX6UL chips.
+	  and APBX-DMA is integrated into some Freescale chips.
 
 config MX3_IPU
 	bool "MX3x Image Processing Unit support"