net: stmmac: always allocate mac_device_info

net: stmmac: always allocate mac_device_info

The ->setup() method implemented by dwmac-loongson and dwmac-sun8i
allocate the mac_device_info structure, as does stmmac_hwif_init().
This makes no sense.

Have stmmac_hwif_init() always allocate this structure, and pass it to
the ->setup() method to initialise when it is provided. Rename this
method to "mac_setup" to more accurately describe what it is doing.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1vImWK-0000000DrIx-28vO@rmk-PC.armlinux.org.uk
Signed-off-by: Paolo Abeni <pabeni@redhat.com>