xtensa: esp32: configure default UART using ROM functions

Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>

drivers/serial/uart_esp32.c

diff --git a/drivers/serial/uart_esp32.c b/drivers/serial/uart_esp32.c
index 70c42db..1966912 100644
--- a/drivers/serial/uart_esp32.c
+++ b/drivers/serial/uart_esp32.c
@@ -41,10 +41,11 @@
 {
 	ARG_UNUSED(dev);
 
+	uartAttach();
+
 	return 0;
 }
 
-
 static const struct uart_driver_api esp32_uart_api = {
 	.poll_in = &esp32_uart_rx,
 	.poll_out = &esp32_uart_tx,