generic: ar8216: reuse the private data from ar8216_probe

The private data of the switch is already
allocated in ar8216_priv, assign that to
each PHY on the same MDIO bus. Also remove
the redundant code from ar8216_config_init.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt@35559 3c298f89-4303-0410-b956-a3cf2f4a3e73
generic: ar8216: don't use ethernet device name in register_switch

The switches are accessed via an MDIO bus. Set the alias
to the name of the MDIO bus, and show that in the message
along with the name of the switch switch device.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt@35560 3c298f89-4303-0410-b956-a3cf2f4a3e73