ARM: dts: allwinner: sun5i-a13-utoo-p66: delete "power-gpios" property

ARM: dts: allwinner: sun5i-a13-utoo-p66: delete "power-gpios" property

The P66's device tree includes the reference design dtsi files, which
defines a node and properties for the touchpanel in the common design.
The P66 dts file then overrides all the properties to match its own
design, but as the touchpanel model is different, a different schema
is matched. This other schema uses a different name for the GPIO.

The original submission added the correct GPIO property, but did not
delete the one inherited from the reference design, causing validation
errors.

Explicitly delete the incorrect GPIO property.

Fixes: 2a53aff27236 ("ARM: dts: sun5i: Enable touchscreen on Utoo P66")
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://patch.msgid.link/20251225103616.3203473-4-wens@kernel.org
Signed-off-by: Chen-Yu Tsai <wens@kernel.org>