extmod/machine: Add MICROPY_PY_MACHINE_PULSE config for time_pulse_us.

Since not all ports that enable the machine module have the pin HAL
functions.

esp8266/mpconfigport.h

@@ -59,6 +59,7 @@
 #define MICROPY_PY_UZLIB            (1)
 #define MICROPY_PY_LWIP             (1)
 #define MICROPY_PY_MACHINE          (1)
+#define MICROPY_PY_MACHINE_PULSE    (1)
 #define MICROPY_PY_MACHINE_I2C      (1)
 #define MICROPY_PY_WEBSOCKET        (1)
 #define MICROPY_PY_WEBREPL          (1)

extmod/machine_pulse.c

@@ -28,7 +28,7 @@
 #include "py/mperrno.h"
 #include "extmod/machine_pulse.h"
 
-#if MICROPY_PY_MACHINE
+#if MICROPY_PY_MACHINE_PULSE
 
 mp_uint_t machine_time_pulse_us(mp_hal_pin_obj_t pin, int pulse_level, mp_uint_t timeout_us) {
     mp_uint_t start = mp_hal_ticks_us();

py/mpconfig.h

@@ -867,6 +867,11 @@ typedef double mp_float_t;
 #define MICROPY_PY_MACHINE (0)
 #endif
 
+// Whether to include: time_pulse_us
+#ifndef MICROPY_PY_MACHINE_PULSE
+#define MICROPY_PY_MACHINE_PULSE (0)
+#endif
+
 #ifndef MICROPY_PY_MACHINE_I2C
 #define MICROPY_PY_MACHINE_I2C (0)
 #endif