drivers: uart: add dma support for ambiq uart driver

This commit adds dma support for ambiq uart driver

Signed-off-by: Hao Luo <[email protected]>

Author: AlessandroLuo

drivers/serial/Kconfig.ambiq

@@ -8,8 +8,20 @@ config UART_AMBIQ
 	depends on SOC_SERIES_APOLLO5X
 	select SERIAL_HAS_DRIVER
 	select SERIAL_SUPPORT_INTERRUPT
+	select SERIAL_SUPPORT_ASYNC
 	select PINCTRL
 	select AMBIQ_HAL
 	select AMBIQ_HAL_USE_UART
 	help
 	  Enable the AMBIQ UART driver.
+
+if UART_AMBIQ
+
+config UART_AMBIQ_HANDLE_CACHE
+	bool "Turn on cache handling in uart driver"
+	default y
+	depends on CACHE_MANAGEMENT && DCACHE
+	help
+	  Disable this if cache has been handled in upper layers.
+
+endif # UART_AMBIQ