mfd: twl: Remove unused inline function twl4030charger_usb_en()

There is no caller in tree, so can remove it.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

include/linux/mfd/twl.h

@@ -781,8 +781,6 @@ int twl4030_sih_setup(struct device *dev, int module, int irq_base);
 #define TWL4030_VAUX3_DEV_GRP		0x1F
 #define TWL4030_VAUX3_DEDICATED		0x22
 
-static inline int twl4030charger_usb_en(int enable) { return 0; }
-
 /*----------------------------------------------------------------------*/
 
 /* Linux-specific regulator identifiers ... for now, we only support