ARM i.MX: introduce imx_otg_ulpi_create to create ULPI transceivers

The boards are currently using otg_ulpi_create and mxc_ulpi_access_ops,
both are only present if CONFIG_USB_ULPI is set. To remove the need of
ifdefs in the board code introduce a imx_otg_ulpi_create functions
which expands to a static inline function if compiled without ulpi.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/arch/arm/mach-mx3/mach-mx31lilly.c b/arch/arm/mach-mx3/mach-mx31lilly.c
index e2f9de1..ed95745 100644
--- a/arch/arm/mach-mx3/mach-mx31lilly.c
+++ b/arch/arm/mach-mx3/mach-mx31lilly.c
@@ -111,8 +111,6 @@
 
 /* USB */
 
-#if defined(CONFIG_USB_ULPI)
-
 #define USB_PAD_CFG (PAD_CTL_DRV_MAX | PAD_CTL_SRE_FAST | PAD_CTL_HYS_CMOS | \
 			PAD_CTL_ODE_CMOS | PAD_CTL_100K_PU)
 
@@ -197,16 +195,13 @@
 
 static void lilly1131_usb_init(void)
 {
-	usbh2_pdata.otg = otg_ulpi_create(&mxc_ulpi_access_ops,
-				ULPI_OTG_DRVVBUS | ULPI_OTG_DRVVBUS_EXT);
-
 	imx31_add_mxc_ehci_hs(1, &usbh1_pdata);
-	imx31_add_mxc_ehci_hs(2, &usbh2_pdata);
-}
 
-#else
-static inline void lilly1131_usb_init(void) {}
-#endif /* CONFIG_USB_ULPI */
+	usbh2_pdata.otg = imx_otg_ulpi_create(ULPI_OTG_DRVVBUS |
+			ULPI_OTG_DRVVBUS_EXT);
+	if (usbh2_pdata.otg)
+		imx31_add_mxc_ehci_hs(2, &usbh2_pdata);
+}
 
 /* SPI */