ARM: dts: stm32: Drop unused linux,wakeup from touchscreen node on DHCOM SoM

Fix the following dtbs_check warning:
touchscreen@38: 'linux,wakeup' does not match any of the regexes: 'pinctrl-[0-9]+'
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Cc: kernel@dh-electronics.com
Cc: linux-stm32@st-md-mailman.stormreply.com
To: linux-arm-kernel@lists.infradead.org
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

arch/arm/boot/dts/stm32mp15xx-dhcom-pdk2.dtsi

@@ -187,7 +187,6 @@ touchscreen@38 {
 		reg = <0x38>;
 		interrupt-parent = <&gpiog>;
 		interrupts = <2 IRQ_TYPE_EDGE_FALLING>; /* GPIO E */
-		linux,wakeup;
 	};
 };