platform/chrome: of_hw_prober: Support touchscreen probing on Squirtle

The MT8186 Squirtle Chromebook is built with one of two possible
touchscreens. Let the prober probe for them.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250421101248.426929-9-wenst@chromium.org


Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>