Following build failed on Linux next arc,

Reported-by: Linux Kernel Functional Testing lkft@linaro.org

Regressions found on arc:

- build/gcc-9-vdk_hs38_smp_defconfig - build/gcc-9-axs103_defconfig

arc-elf32-ld: drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.o: in function `stmmac_mdio_unregister': stmmac_mdio.c:(.text+0xe74): undefined reference to `lynx_pcs_destroy' arc-elf32-ld: stmmac_mdio.c:(.text+0xe74): undefined reference to `lynx_pcs_destroy' make[2]: *** [/builds/linux/scripts/Makefile.vmlinux:35: vmlinux] Error 1

Build log: ======== - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20230606/tes... - https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20230606/tes...

-- Linaro LKFT https://lkft.linaro.org