mediatek: filogic: replace built-in Aquantia driver with module

mediatek: filogic: replace built-in Aquantia driver with module

Some Aquantia PHYs (e.g. AQR113C) require firmware to be uploaded by
host system. With built-in drivers this doesn't work in OpenWrt /
embeddded as filesystem isn't available during PHY probe. That results
in delays like:
[    1.588068] Aquantia AQR113C mdio-bus:00: Falling back to sysfs fallback for: Rhe-05.06-Candidate9-AQR_Mediatek_23B_P5_ID45824_LCLVER1.cld
[   64.526387] Aquantia AQR113C mdio-bus:00: failed to find FW file Rhe-05.06-Candidate9-AQR_Mediatek_23B_P5_ID45824_LCLVER1.cld (-110)

Switch to module to postpone PHY probe to init state.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>