stmmac: socfpga: remove extra call to socfpga_dwmac_setup

In the socfpga_dwmac_probe function, we have a call to socfpga_dwmac_setup,
which is already called from socfpga_dwmac_init later in the probe function.
Remove this extra call to socfpga_dwmac_setup.

Also we should not be calling socfpga_dwmac_setup() directly without wrapping
it around the proper reset assert/deasserts. That is because the
socfpga_dwmac_setup() is setting up PHY modes in the system manager, and it
is requires the EMAC's to be in reset during the PHY setup.

Reported-by: Matthew Gerlach <mgerlach@opensource.altera.com>
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: David S. Miller <davem@davemloft.net>