linux/mdio.h: Sync with Linux kernel v4.17

This syncs U-Boot's include/linux/mdio.h with Linux kernel v4.17
include/uapi/linux/mdio.h.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
1 file changed