SPEAr: Enable autoneg for ethernet

SPEAr: Enable autoneg for ethernet

Enabling autoneg avoids situation on few phys with fixed configuration. For
example, in one situation, nfs boot timed out when phy configuration is 100Mbps.
In another situtation, when traffic is directed to SPEAr, either thru
cross-cable or thru switch, the TFTP or DHCP command in u-boot starts to timeout
very often.

When Autoneg is ON, same phys started working perfectly.

Reported-by: Deepak Sikri <deepak.sikri@st.com>
Reported-by: Armando Visconti <armando.visconti@st.com>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: Amit Virdi <amit.virdi@st.com>
Signed-off-by: Stefan Roese <sr@denx.de>