pinctrl: samsung: Add filter selection support for alive bank on gs101

pinctrl: samsung: Add filter selection support for alive bank on gs101

Newer Exynos based SoCs have a filter selection bitfield in the filter
configuration registers on alive bank pins. This allows the selection of
a digital or analog delay filter for each pin. Add support for selecting
and enabling the filter.

On suspend we set the analog filter to all pins in the bank (as the
digital filter relies on a clock). On resume the digital filter is
reapplied to all pins in the bank. The digital filter is working via
a clock and has an adjustable filter delay flt_width bitfield, whereas
the analog filter uses a fixed delay.

The filter determines to what extent signal fluctuations received through
the pad are considered glitches.

The code path can be exercised using
echo mem > /sys/power/state
And then wake the device using a eint gpio

Reviewed-by: André Draszik <andre.draszik@linaro.org>
Signed-off-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://lore.kernel.org/r/20250402-pinctrl-fltcon-suspend-v6-4-78ce0d4eb30c@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>