stmmac: GMAC_RGSMIIIS reports bogus values

[Giuseppe CAVALLARO]

On 1/27/2017 11:23 AM, Alexey Brodkin wrote:
> That's why my initial proposal was to ignore whatever we read from this register
> if we have MDIO bus instantiated already.

sorry for my late reply, I agree with this approach, according to the
HW and platform configuration the driver has to understand and then
work to use either SMA or PCS module.

Regards
Peppe