net: stmmac: socfpga: call set_phy_mode() before registration

Initialisation/setup after registration is a bug. This is the second
of two patches fixing this in socfpga.

The set_phy_mode() functions do various hardware setup that would
interfere with a netdev that has been published, and thus available to
be opened by the kernel/userspace.

However, set_phy_mode() relies upon the netdev having been initialised
to get at the plat_stmmacenet_data structure, which is probably why it
was placed after stmmac_drv_probe(). We can remove that need by storing
a pointer to struct plat_stmmacenet_data in struct socfpga_dwmac.

Move the call to set_phy_mode() before calling stmmac_dvr_probe().
This also simplifies the probe function as there is no need to
unregister the netdev if set_phy_mode() fails.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Tested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/E1u5Snn-001IJq-L0@rmk-PC.armlinux.org.uk


Signed-off-by: Jakub Kicinski <kuba@kernel.org>