ARM: dts: stm32: Add alternate pinmux for sai2b on stm32mp15

Add another option for the SAI2B pins.

This is used on the Phycore STM32MP1.
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Reviewed-by: Olivier Moysan <olivier.moysan@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

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

@@ -1491,6 +1491,30 @@ pins {
 		};
 	};
 
+	sai2b_pins_d: sai2b-3 {
+		pins1 {
+			pinmux = <STM32_PINMUX('H', 2, AF10)>, /* SAI2_SCK_B */
+				 <STM32_PINMUX('C', 0, AF8)>, /* SAI2_FS_B */
+				 <STM32_PINMUX('H', 3, AF10)>; /* SAI2_MCLK_B */
+			slew-rate = <0>;
+			drive-push-pull;
+			bias-disable;
+		};
+		pins2 {
+			pinmux = <STM32_PINMUX('F', 11, AF10)>; /* SAI2_SD_B */
+			bias-disable;
+		};
+	};
+
+	sai2b_sleep_pins_d: sai2b-sleep-3 {
+		pins1 {
+			pinmux = <STM32_PINMUX('H', 2, ANALOG)>, /* SAI2_SCK_B */
+				 <STM32_PINMUX('C', 0, ANALOG)>, /* SAI2_FS_B */
+				 <STM32_PINMUX('H', 3, ANALOG)>, /* SAI2_MCLK_B */
+				 <STM32_PINMUX('F', 11, ANALOG)>; /* SAI2_SD_B */
+		};
+	};
+
 	sai4a_pins_a: sai4a-0 {
 		pins {
 			pinmux = <STM32_PINMUX('B', 5, AF10)>; /* SAI4_SD_A */