arm64: dts: qcom: sc7280: Hook up the touchscreen IO rail on villager

arm64: dts: qcom: sc7280: Hook up the touchscreen IO rail on villager

On never revs of sc7280-herobrine-villager (rev2+) the L3C rail is
provided to the touchscreen as the IO voltage rail. Let's add it in
the device tree.

NOTE: Even though this is only really needed on rev2+ villagers (-rev0
had non-functioning touchscreen and -rev1 had some hacky hardware
magic), it doesn't actually hurt to do this for old villager revs. As
talked about in the patch ("arm64: dts: qcom: sc7280: On QCard,
regulator L3C should be 1.8V") the L3C regulator didn't go anywhere at
all on older revs. That means that turning it on for older revs
doesn't hurt other than drawing a tiny bit of extra power. Since -rev0
and -rev1 villagers will never make it to real customers and it's nice
not to have too many old device trees, the better tradeoff seems to be
to enable it everywhere.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230206184744.3.I740d409bc5bb69bf4a7b3c4568ea6e7a92f16ccd@changeid