ARM: DT: STiH407: Add SPI FSM (NOR Flash) Controller pin config

This patch adds the pin configuration for the NOR flash controller.

Signed-off-by: Christophe Kerello <christophe.kerello@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>