shell: uart: Rework Kconfig dependencies

When UART asynchronous API support was added to shell it was set up
to be the default one and was turning on asynchronous API if it was
supported. However, it may lead to complation failures if device
requires additional setup for asynchronous UART (e.g DMA in device
tree). Becuase of that, it is reverted back to use interrupt driven
API and use asynchronous API if it is already enabled in the
application.

Signed-off-by: Krzysztof Chruściński <[email protected]>

subsys/shell/backends/Kconfig.backends

@@ -44,12 +44,13 @@ config SHELL_PROMPT_UART
 
 config SHELL_BACKEND_SERIAL_INTERRUPT_DRIVEN
 	bool "Interrupt driven"
+	default y
 	depends on SERIAL_SUPPORT_INTERRUPT
 
 choice SHELL_BACKEND_SERIAL_API
 	prompt "Mode"
-	default SHELL_BACKEND_SERIAL_API_ASYNC if SERIAL_SUPPORT_ASYNC
-	default SHELL_BACKEND_SERIAL_API_INTERRUPT_DRIVEN if SERIAL_SUPPORT_INTERRUPT
+	default SHELL_BACKEND_SERIAL_API_ASYNC if UART_ASYNC_API
+	default SHELL_BACKEND_SERIAL_API_INTERRUPT_DRIVEN if SHELL_BACKEND_SERIAL_INTERRUPT_DRIVEN
 	default SHELL_BACKEND_SERIAL_API_POLLING
 
 config SHELL_BACKEND_SERIAL_API_POLLING
@@ -65,7 +66,6 @@ config SHELL_BACKEND_SERIAL_API_ASYNC
 	bool "Asynchronous"
 	depends on SERIAL_SUPPORT_ASYNC
 	select UART_ASYNC_RX_HELPER
-	select UART_ASYNC_API
 
 endchoice