net: stmmac: mediatek: convert to resume() method

net: stmmac: mediatek: convert to resume() method

Convert mediatek to use the resume() platform method rather than the
init() platform method as mediatek_dwmac_init() is only called from
the resume paths.

This will ensure that in a future commit, mediatek_dwmac_init() won't
be called when probing the main part of the stmmac driver.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/E1ulXcC-008grN-Hc@rmk-PC.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>