esp8266: Implement software SPI class.
Supports speeds up to 500k baud, polarity=0/1, phase=0/1, and using any
pins. Only supports MSB output at the moment.
diff --git a/esp8266/modpyb.h b/esp8266/modpyb.h
index e691805..7b8f887 100644
--- a/esp8266/modpyb.h
+++ b/esp8266/modpyb.h
@@ -2,6 +2,7 @@
extern const mp_obj_type_t pyb_adc_type;
extern const mp_obj_type_t pyb_rtc_type;
extern const mp_obj_type_t pyb_i2c_type;
+extern const mp_obj_type_t pyb_spi_type;
typedef struct _pyb_pin_obj_t {
mp_obj_base_t base;