ARM: imx: move EHCI platform defines out of platform_data header

The platform_data header usb-ehci-mxc.h has a lot of stuff used by only
IMX platform code.  They shouldn't be really in this header but a IMX
platform local header.  Create ehci.h and move these stuff into it.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>

arch/arm/mach-imx/mach-mx31moboard.c

@@ -47,6 +47,7 @@
 #include "board-mx31moboard.h"
 #include "common.h"
 #include "devices-imx31.h"
+#include "ehci.h"
 #include "hardware.h"
 #include "iomux-mx3.h"
 #include "ulpi.h"