arm64: dts: mt6358: Drop bogus "regulator-fixed" compatible properties

arm64: dts: mt6358: Drop bogus "regulator-fixed" compatible properties

Whether a regulator under the MT6358 PMIC is a fixed regulator or not is
derived from the node name. Compatible string properties are not used.
This causes validation errors after the regulator binding is converted
to DT schema.

Drop the bogus "regulator-fixed" compatible properties from the PMIC's
regulator sub-nodes.

Fixes: 9f8872221674 ("arm64: dts: mt6358: add PMIC MT6358 related nodes")
Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20231130074032.913511-3-wenst@chromium.org
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>