message: MMA7660: changed mraa i2c read call
  The mraa_i2c_read_bytes_call didn't work with firmata based
  platforms and was changed to mraa_i2c_read_bytes_data call which
  worked.
diff: @@ -99,13 +99,14 @@ upm_result_t mma7660_write_byte(const mma7660_context dev,
  upm_result_t mma7660_read_byte(const mma7660_context dev, uint8_t reg,
  uint8_t *byte)
  {
  + uint8_t data[11];
  assert(dev != NULL);
  - int x = mraa_i2c_read_byte_data(dev->i2c, reg);
  + int ret = mraa_i2c_read_bytes_data(dev->i2c, 0x00, data, 11);
  - if (x < 0)
  - {
  - printf("%s: mraa_i2c_read_byte_data() failed.\n", __FUNCTION__);
  + if (ret != 11) {
  + printf("%s: mraa_i2c_read_bytes_data() failed.\n", __FUNCTION__);
  + printf("returned %d bytes upon read\n", ret);
  if (byte)
  *byte = 0;
  @@ -113,7 +114,7 @@ upm_result_t mma7660_read_byte(const mma7660_context dev, uint8_t reg,
  }
  if (byte)
  - *byte = (uint8_t)(x & 0xff);
  + *byte = (uint8_t)(data[reg] & 0xff);
  return UPM_SUCCESS;
  }
  