pinctrl: devicetree: Add one new attribute description and rename another two

pinctrl: devicetree: Add one new attribute description and rename another two

Fixes the following W=1 kernel build warning(s):

 drivers/pinctrl/devicetree.c:27: warning: Function parameter or member 'map' not described in 'pinctrl_dt_map'
 drivers/pinctrl/devicetree.c:27: warning: Function parameter or member 'num_maps' not described in 'pinctrl_dt_map'
 drivers/pinctrl/devicetree.c:409: warning: Function parameter or member 'out_args' not described in 'pinctrl_parse_index_with_args'
 drivers/pinctrl/devicetree.c:409: warning: Excess function parameter 'out_arts' description in 'pinctrl_parse_index_with_args'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200713144930.1034632-14-lee.jones@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>