Usb Compilation error

Hello,

While compiling usb drivers i have errors, can you please help if anybody know about it.

arm-openwrt-linux-muslgnueabi-ld: drivers/usb/host/usb20/musb_core.o: in function `musb_readb':
target-arm_cortex-a7+neon-vfpv4_musl_eabi/linux-mediatek_mt7623/linux-4.14.154/./include/linux/musb/musb_io.h:121: undefined reference to `usb_enable_clock'
arm-openwrt-linux-muslgnueabi-ld: target-arm_cortex-a7+neon-vfpv4_musl_eabi/linux-mediatek_mt7623/linux-4.14.154/./include/linux/musb/musb_io.h:124: undefined reference to `usb_enable_clock'
arm-openwrt-linux-muslgnueabi-ld: drivers/usb/host/usb20/musb_core.o: in function `musb_suspend_noirq':
target-arm_cortex-a7+neon-vfpv4_musl_eabi/linux-mediatek_mt7623/linux-4.14.154/drivers/usb/host/usb20/musb_core.c:2340: undefined reference to `usb_enable_clock'
arm-openwrt-linux-muslgnueabi-ld: drivers/usb/host/usb20/musb_core.o: in function `musb_readl':
target-arm_cortex-a7+neon-vfpv4_musl_eabi/linux-mediatek_mt7623/linux-4.14.154/./include/linux/musb/musb_io.h:72: undefined reference to `usb_enable_clock'
arm-openwrt-linux-muslgnueabi-ld: target-arm_cortex-a7+neon-vfpv4_musl_eabi/linux-mediatek_mt7623/linux-4.14.154/./include/linux/musb/musb_io.h:75: undefined reference to `usb_enable_clock'
arm-openwrt-linux-muslgnueabi-ld: drivers/usb/host/usb20/musb_core.o:target-arm_cortex-a7+neon-vfpv4_musl_eabi/linux-mediatek_mt7623/linux-4.14.154/./include/linux/musb/musb_io.h:121: more undefined references to `usb_enable_clock' follow
arm-openwrt-linux-muslgnueabi-ld: drivers/usb/host/usb20/musb_core.o: in function `musb_suspend_noirq':
target-arm_cortex-a7+neon-vfpv4_musl_eabi/linux-mediatek_mt7623/linux-4.14.154/drivers/usb/host/usb20/musb_core.c:2343: undefined reference to `usb_phy_context_save'
arm-openwrt-linux-muslgnueabi-ld: target-arm_cortex-a7+neon-vfpv4_musl_eabi/linux-mediatek_mt7623/linux-4.14.154/drivers/usb/host/usb20/musb_core.c:2346: undefined reference to `usb_enable_clock'