ARM: DT: STiH407: Add pinconfig for IRB UHF and IRB TX

This patch adds the pinconfig for IRB TX and IRB UHF.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@st.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Signed-off-by: Maxime Coquelin <maxime.coquelin@st.com>