serial: stm32x7: add STM32H7 support

STM32F7 and STM32H7 shares the same UART block, add
STM32H7 compatible string.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/serial/Kconfig

@@ -531,10 +531,11 @@ config STI_ASC_SERIAL
 
 config STM32X7_SERIAL
 	bool "STMicroelectronics STM32 SoCs on-chip UART"
-	depends on DM_SERIAL && STM32F7
+	depends on DM_SERIAL && (STM32F7 || STM32H7)
 	help
-	  If you have a machine based on a STM32 F7 you can enable its
-	  onboard serial ports, say Y to this option. If unsure, say N.
+	  If you have a machine based on a STM32 F7 or H7 SoC you can
+	  enable its onboard serial ports, say Y to this option.
+	  If unsure, say N.
 
 config MPC8XX_CONS
 	bool "Console driver for MPC8XX"

drivers/serial/serial_stm32x7.c

@@ -112,6 +112,8 @@ static int stm32_serial_probe(struct udevice *dev)
 static const struct udevice_id stm32_serial_id[] = {
 	{.compatible = "st,stm32f7-usart"},
 	{.compatible = "st,stm32f7-uart"},
+	{.compatible = "st,stm32h7-usart"},
+	{.compatible = "st,stm32h7-uart"},
 	{}
 };