[nrf fromtree] drivers: serial: nrfx_uarte: Remove unused element from a structure

Remove aborted flag from uarte_async_rx structure. Flag is not
used.

Signed-off-by: Krzysztof Chruściński <[email protected]>
(cherry picked from commit cfc87da)

Author: nordic-krch

drivers/serial/uart_nrfx_uarte.c

@@ -162,7 +162,6 @@ struct uarte_async_rx {
 	uint8_t flush_cnt;
 	volatile bool enabled;
 	volatile bool discard_fifo;
-	volatile bool aborted;
 };
 
 struct uarte_async_cb {