stmmac: fix adjust link call in case of a switch is attached

While initializing the phy, the stmmac driver sets the
PHY_IGNORE_INTERRUPT so the PAL won't call the adjust hook
that is needed, on some platforms, e.g. STi, to invoke the glue.

The patch allows the PAL to poll the stmmac_adjust_link just one time
in case of a switch is attached, setting later the PHY_IGNORE_INTERRUPT
flag.
Moving this kind of logic inside the adjust_link it makes sense to
anticipate the check for EEE that will never initialized in this
scenario.

Reported-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Tested-by: Gabriel Fernandez <gabriel.fernandez@linaro.org>
Cc: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>