ARM: dts: stm32: stm32mp15-pinctrl: add spi1-1 pinmux group

Add spi1-1 pingroup as preparation for Protonic PRTT1C board.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

arch/arm/boot/dts/stm32mp15-pinctrl.dtsi

@@ -2261,4 +2261,19 @@ pins2 {
 			bias-disable;
 		};
 	};
+
+	spi1_pins_b: spi1-1 {
+		pins1 {
+			pinmux = <STM32_PINMUX('A', 5, AF5)>, /* SPI1_SCK */
+				 <STM32_PINMUX('B', 5, AF5)>; /* SPI1_MOSI */
+			bias-disable;
+			drive-push-pull;
+			slew-rate = <1>;
+		};
+
+		pins2 {
+			pinmux = <STM32_PINMUX('A', 6, AF5)>; /* SPI1_MISO */
+			bias-disable;
+		};
+	};
 };