pinctrl: actions: pinctrl-s900: Constify s900_padinfo[]

pinctrl: actions: pinctrl-s900: Constify s900_padinfo[]

The only usage of s900_padinfo[] is to assign it to the padinfo field in
the owl_pinctrl_soc_data struct, which is a const pointer. Make it const
to allow the compiler to put it in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200830224311.36994-4-rikard.falkeborn@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>