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/ehci-imx31.c

@@ -17,6 +17,7 @@
 #include <linux/io.h>
 #include <linux/platform_data/usb-ehci-mxc.h>
 
+#include "ehci.h"
 #include "hardware.h"
 
 #define USBCTRL_OTGBASE_OFFSET	0x600