ARM: dts: stm32: Add alternate pinmux for SPI2 pins

Add another mux option for SPI2 pins, this is used on AV96 board.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: linux-stm32@st-md-mailman.stormreply.com
To: linux-arm-kernel@lists.infradead.org
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

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

@@ -1559,6 +1559,21 @@
 		};
 	};
 
+	spi2_pins_a: spi2-0 {
+		pins1 {
+			pinmux = <STM32_PINMUX('B', 10, AF5)>, /* SPI1_SCK */
+				 <STM32_PINMUX('I', 3, AF5)>; /* SPI1_MOSI */
+			bias-disable;
+			drive-push-pull;
+			slew-rate = <1>;
+		};
+
+		pins2 {
+			pinmux = <STM32_PINMUX('I', 2, AF5)>; /* SPI1_MISO */
+			bias-disable;
+		};
+	};
+
 	usart2_pins_a: usart2-0 {
 		pins1 {
 			pinmux = <STM32_PINMUX('F', 5, AF7)>, /* USART2_TX */