mii: Allow NIC drivers to pass more information to MII probe

mii: Allow NIC drivers to pass more information to MII probe

- mii_capmask, which is used to mask out uninstended BMSR bits.
- At which PHYs that MII should perform probing and attching
  (mii_probe_args.mii_probemask).
- mii_flags, which will be used for future mii flow control support.

Th he above information could only be passed using new mii_probe(),
it should be used in the following way:

struct mii_probe_args mii_args;

mii_probe_args_init(&mii_args, ifmedia_upd, ifmedia_sts);
/*
 * Adjust mii_args if necessary
 */
error = mii_probe(dev, &mii_dev, &mii_args);

Inspired-by: FreeBSD 213878