omap: usb: fix build warning

Fix this and similar build warnings when building with
omap_4430sdp_defconfig.

 CC      arch/arm/mach-omap2/board-4430sdp.o
In file included from arch/arm/mach-omap2/board-4430sdp.c:36:
arch/arm/plat-omap/include/plat/usb.h:109: warning: return type defaults to 'int'
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Acked-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/plat-omap/include/plat/usb.h

@@ -105,7 +105,7 @@ static inline void omap1_usb_init(struct omap_usb_config *pdata)
 #if defined(CONFIG_ARCH_OMAP_OTG) || defined(CONFIG_ARCH_OMAP_OTG_MODULE)
 void omap2_usbfs_init(struct omap_usb_config *pdata);
 #else
-static inline omap2_usbfs_init(struct omap_usb_config *pdata)
+static inline void omap2_usbfs_init(struct omap_usb_config *pdata)
 {
 }
 #endif