stmmac: update version to Oct_2015

This patch just updates the driver to the version fully
tested on STi platforms. This version is Oct_2015.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>