drivers: serial: nrfx_uarte: Default DIRECT_ISR if MULTITHREADING=n

Default to using DIRECT_ISR if nothreading. This allows the SW ISR
table to be excluded if nothreading.

Signed-off-by: Bjarki Arge Andreasen <[email protected]>

Author: bjarki-andreasen

drivers/serial/Kconfig.nrfx

@@ -81,6 +81,7 @@ config UART_ASYNC_TX_CACHE_SIZE
 
 config UART_NRFX_UARTE_DIRECT_ISR
 	bool "Use direct ISR"
+	default y if !MULTITHREADING
 
 config UART_NRFX_UARTE_SPURIOUS_RXTO_WORKAROUND
 	bool