ARM: imx: depend MXC debug board on 3DS machines

Depend the MXC debug board on machines which actually support it.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 178f0d0..bf42a6a 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -21,6 +21,7 @@
 
 config MXC_DEBUG_BOARD
 	bool "Enable MXC debug board(for 3-stack)"
+	depends on MACH_MX27_3DS || MACH_MX31_3DS || MACH_MX35_3DS
 	help
 	  The debug board is an integral part of the MXC 3-stack(PDK)
 	  platforms, it can be attached or removed from the peripheral