Fix SPI speed for MPU6000 for CC3D target and some new targets

src/main/drivers/accgyro_spi_mpu6000.c

@@ -132,6 +132,8 @@ void mpu6000SpiGyroInit(uint8_t lpf)
     mpu6000WriteRegister(MPU6000_CONFIG, lpf);
     delayMicroseconds(1);
 
+    spiSetDivisor(MPU6000_SPI_INSTANCE, SPI_18MHZ_CLOCK_DIVIDER);  // 18 MHz SPI clock
+
     int16_t data[3];
     mpuGyroRead(data);