pinctrl: SPEAr320: Correct pad mux entries for rmii/smii

pin entries of rmii and smii are interchanged by mistake. Fix it.

Signed-off-by: Deepak Sikri <deepak.sikri@st.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>