pinctrl: clarify some dt pinconfig options

The bias-pull-* options use values > 0 to indicate that the pull should
be activated and optionally also indicate the strength of the pull.
Therefore use an default value of 1 for these options.

Split the low-power-mode option into low-power-enable and -disable.

Update the documentation to describe the param arguments better.

Reported-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git


Git-commit: 9ee1f7d266aa1e2bfeb20cb5d4ac299c
Change-Id: If16f7a091e4b1952b48c36de9bf3928b2455c24f
Signed-off-by: Hanumant Singh <hanumant@codeaurora.org>