pinctrl: pinconf-generic: sort pin configuration params alphabetically

Currently, the dt_params array in drivers/pinctrl/pinconf-generic.c
is not sorted in the same order as the enum pin_config_param in
include/linux/pinctrl/pinconf-generic.h.

Sort enum pin_config_param, conf_items, dt_params, alphabetically
for consistency.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>