IPQ8074 requires the PHY to be powered on before accessing DBI registers.
It's not clear whether other variants have the same dependency, but there
seems to be no reason for them to be different, so move all the DBI
accesses from .init() to .post_init() so they are all after phy_power_on().

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20220623155004.688090-2-robimarko@gmail.comSigned-off-by: NRobert Marko <robimarko@gmail.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>