[PATCH RESEND] rockchip: Make gpiod pin control work and add gpio-ranges

[Matthijs Kooijman]

Hi folks,

This is a resend of a two patches I submitted last december. Lacking any
replies, I'm resending it (and also explicitly sending it to the GPIO
subsystem maintainers Linus and Bartosz this time - I'm still a bit
unsure whom to address exactly).

The first patch fixes pin config (e.g. bias) done by userspace via the
gpiod interface, which was not implemented for all rockchip boards.

The second patch is just because I was messing with this code already
and had a test setup ready. It makes gpio-ranges explicit for the rk3308
instead of relying on the (possibly fragile) legacy workaround in
gpio-rockchip to add them automatically. I tested this be removing the
legacy workaround from the code during my testing.

I think the first patch might be a good candidate to backport to the
stable releases, since it makes a userspace interface functional that
currently silently fails. However, it is not a clear bugfix and I am not
super familiar with the rules for -stable, so I left out any stable Cc
tags. Feel free to add them if this seems appropriate.

Both patches were tested on a rock pi s with a rk3308.

Gr.

Matthijs