Add documentation of new GPIO specifiers indicating if the state of an
output pin should be maintained during sleep/low-power mode.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>