dts: stm32u5: Add SW/JTAG debug port node

Provide jtag port pins description, so they can be used to be set in
analog mode when not required to save power (around 40uA saved in total).

Signed-off-by: Erwan Gouriou <erwan.gouriou@st.com>

dts/arm/st/u5/stm32u5.dtsi

@@ -269,6 +269,16 @@
 				reg = <0x42022000 0x400>;
 				clocks = <&rcc STM32_CLOCK_BUS_AHB2 0x00000100>;
 			};
+
+			swj_port: swj_port {
+				compatible = "gpio-jtag";
+				pinctrl-0 = <&debug_jtms_swdio_pa13 &debug_jtck_swclk_pa14
+					     &debug_jtdi_pa15 &debug_jtdo_swo_pb3
+					     &debug_jtrst_pb4>;
+				pinctrl-1 = <&analog_pa13 &analog_pa14 &analog_pa15
+					     &analog_pb3 &analog_pb4>;
+				pinctrl-names = "default", "sleep";
+			};
 		};
 
 		iwdg: watchdog@40003000 {