ARM: dts: stm32: add pin map for LTDC on stm32f7

Add pin configurations for using LTDC (LCD-tft Display Controller) on
stm32f746-disco board.
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Raphaël Gallais-Pou <raphael.gallais-pou@foss.st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

arch/arm/boot/dts/st/stm32f7-pinctrl.dtsi

@@ -375,6 +375,41 @@ pins2 {
 					bias-pull-up;
 				};
 			};
+
+
+			ltdc_pins_a: ltdc-0 {
+				pins {
+					pinmux = <STM32_PINMUX('E', 4, AF14)>, /* LCD_B0 */
+						 <STM32_PINMUX('G',12, AF9)>,  /* LCD_B4 */
+						 <STM32_PINMUX('I', 9, AF14)>, /* LCD_VSYNC */
+						 <STM32_PINMUX('I',10, AF14)>, /* LCD_HSYNC */
+						 <STM32_PINMUX('I',14, AF14)>, /* LCD_CLK */
+						 <STM32_PINMUX('I',15, AF14)>, /* LCD_R0 */
+						 <STM32_PINMUX('J', 0, AF14)>, /* LCD_R1 */
+						 <STM32_PINMUX('J', 1, AF14)>, /* LCD_R2 */
+						 <STM32_PINMUX('J', 2, AF14)>, /* LCD_R3 */
+						 <STM32_PINMUX('J', 3, AF14)>, /* LCD_R4 */
+						 <STM32_PINMUX('J', 4, AF14)>, /* LCD_R5 */
+						 <STM32_PINMUX('J', 5, AF14)>, /* LCD_R6 */
+						 <STM32_PINMUX('J', 6, AF14)>, /* LCD_R7 */
+						 <STM32_PINMUX('J', 7, AF14)>, /* LCD_G0 */
+						 <STM32_PINMUX('J', 8, AF14)>, /* LCD_G1 */
+						 <STM32_PINMUX('J', 9, AF14)>, /* LCD_G2 */
+						 <STM32_PINMUX('J',10, AF14)>, /* LCD_G3 */
+						 <STM32_PINMUX('J',11, AF14)>, /* LCD_G4 */
+						 <STM32_PINMUX('J',13, AF14)>, /* LCD_B1 */
+						 <STM32_PINMUX('J',14, AF14)>, /* LCD_B2 */
+						 <STM32_PINMUX('J',15, AF14)>, /* LCD_B3 */
+						 <STM32_PINMUX('K', 0, AF14)>, /* LCD_G5 */
+						 <STM32_PINMUX('K', 1, AF14)>, /* LCD_G6 */
+						 <STM32_PINMUX('K', 2, AF14)>, /* LCD_G7 */
+						 <STM32_PINMUX('K', 4, AF14)>, /* LCD_B5 */
+						 <STM32_PINMUX('K', 5, AF14)>, /* LCD_B6 */
+						 <STM32_PINMUX('K', 6, AF14)>, /* LCD_B7 */
+						 <STM32_PINMUX('K', 7, AF14)>; /* LCD_DE */
+					slew-rate = <2>;
+				};
+			};
 		};
 	};
 };