ARM: ux500: use #include syntax to include *.dtsi.

This patch prepares the use of '#define' into dts files.

Signed-off-by: Gabriel Fernandez <gabriel.fernandez@st.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>