ARM: dts: stm32: Add alternate pinmux for UART5 pins

Add another mux option for UART5 pins, this is used on DRC Compact board.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Patrice Chotard <patrice.chotard@foss.st.com>
Cc: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/arch/arm/dts/stm32mp15-pinctrl.dtsi b/arch/arm/dts/stm32mp15-pinctrl.dtsi
index dc329bf..6a5b401 100644
--- a/arch/arm/dts/stm32mp15-pinctrl.dtsi
+++ b/arch/arm/dts/stm32mp15-pinctrl.dtsi
@@ -1865,6 +1865,19 @@
 		};
 	};
 
+	uart5_pins_a: uart5-0 {
+		pins1 {
+			pinmux = <STM32_PINMUX('B', 13, AF14)>; /* UART5_TX */
+			bias-disable;
+			drive-push-pull;
+			slew-rate = <0>;
+		};
+		pins2 {
+			pinmux = <STM32_PINMUX('B', 5, AF12)>; /* UART5_RX */
+			bias-disable;
+		};
+	};
+
 	uart7_pins_a: uart7-0 {
 		pins1 {
 			pinmux = <STM32_PINMUX('E', 8, AF7)>; /* UART7_TX */