ARM: ux500: move AB8500 clock out pins to DT

This moves the AB8500 pin settings for the clock out pins over
to the device tree. We can delete the special setup calls for the
platforms only using the AB8500 and not AB8505.

Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>