ehci-mxc: Define host offsets

Some MXC SoCs like the i.MX35 have hosts located at unusual offsets, so prepare
to the introduction of i.MX35 support by defining the ehci-mxc hosts offsets at
SoC level.

Signed-off-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/include/asm/arch-mx31/imx-regs.h b/arch/arm/include/asm/arch-mx31/imx-regs.h
index 01a849d..ae3658b 100644
--- a/arch/arm/include/asm/arch-mx31/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx31/imx-regs.h
@@ -895,6 +895,7 @@
 
 #define MX31_AIPS1_BASE_ADDR	0x43f00000
 #define IMX_USB_BASE		(MX31_AIPS1_BASE_ADDR + 0x88000)
+#define IMX_USB_PORT_OFFSET	0x200
 
 /*
  * CSPI register definitions