musb: fix compilation warning

Fixes below compilation warning
omap3.c: In function 'musb_platform_init':
omap3.c:123: warning: implicit declaration of function
			'omap3_evm_need_extvbus'

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Acked-by: Remy Bohmer <linux@bohmer.net>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

drivers/usb/musb/omap3.h

@@ -45,7 +45,7 @@
 int musb_platform_init(void);
 
 #ifdef CONFIG_OMAP3_EVM
-extern u8 omap3_evm_use_extvbus(void);
+extern u8 omap3_evm_need_extvbus(void);
 #endif
 
 #endif /* _MUSB_OMAP3_H */