esp32/machine_uart: Implement Python UART IRQ with IRQ_RX and IRQ_BREAK.

Supported trigger events: IRQ_RX and IRQ_BREAK.  Hard IRQ is not supported.

Signed-off-by: robert-hh <robert@hammelrath.com>
diff --git a/ports/esp32/mpconfigport.h b/ports/esp32/mpconfigport.h
index 5051afb..a5c6b9c 100644
--- a/ports/esp32/mpconfigport.h
+++ b/ports/esp32/mpconfigport.h
@@ -155,6 +155,7 @@
 #define MICROPY_PY_MACHINE_UART             (1)
 #define MICROPY_PY_MACHINE_UART_INCLUDEFILE "ports/esp32/machine_uart.c"
 #define MICROPY_PY_MACHINE_UART_SENDBREAK   (1)
+#define MICROPY_PY_MACHINE_UART_IRQ         (1)
 #define MICROPY_PY_MACHINE_WDT              (1)
 #define MICROPY_PY_MACHINE_WDT_INCLUDEFILE  "ports/esp32/machine_wdt.c"
 #define MICROPY_PY_NETWORK (1)