This converts the ABx500 pin controller and all associated device
trees to use the standard, generic mux bindings for pin controllers.
There are no such device trees deployed in the wild so this is
safe to do to set a good example.
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>

This moves the set-up of the HREF500 with its AB8505 ASIC to
a device tree include. Since there is not yet any device tree
for this board the DTSI is currently unused. After this delete
the board file for pins for good and migration of pins to the
device tree is complete.

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