Ensure Redbear Blend2/Nano2 have i2c headers
#include "flash_map/flash_map.h"
#include "hal/hal_flash.h"
#include "hal/hal_spi.h"
+#include "hal/hal_i2c.h"
#include "hal/hal_watchdog.h"
#if MYNEWT_VAL(UART_0) || MYNEWT_VAL(UART_1)
#include "uart/uart.h"
