pinctrl: tegra: Display pin function in pinconf-groups

commit 0bbac626d9332ac221dbc2cebfbed2c6a801d381 from
https://nv-tegra.nvidia.com/r/3rdparty/canonical/linux-jammy.git jetson_36.3

BugLink: https://bugs.launchpad.net/bugs/2042935

The function that a pin is muxed to can be read from the top-level
pinctrl-maps debugfs file. However, this only reflects the values that
were specified in device tree, so they will only show deviations from
the hardware default setting. Display the current pinmux setting in the
per-controller pinconf-groups debugfs file along with the rest of the
per-pin configuration settings.

http://nvbugs/4328896
http://nvbugs/4307643

Signed-off-by: Thierry Reding <treding@nvidia.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://lore.kernel.org/r/20230929122101.466266-1-thierry.reding@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

(cherry picked from commit bf800ca4

)
Signed-off-by: Prathamesh Shete <pshete@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Jacob Martin <jacob.martin@canonical.com>
Acked-by: Noah Wager <noah.wager@canonical.com>
Signed-off-by: Jacob Martin <jacob.martin@canonical.com>
Signed-off-by: Rajeshkumar Ramasamy <rajeshkumar.ramasamy@windriver.com>