Initial build for Crazyflie 2.0

Working crazyflie firmware build

* Console on USART3
* Could not disable building PX4IO firmware, currently commented out

Don't build PX4IO firmware if the board doesn't ask for it

Added crazyflie motor driver

Fixed wrong register

CLK_SEL is in PWR_MGMT_1

Initial I2C/SPI MPU9250 device

* Tested with I2C
* Need to add error checking
* Intermittent crash on stop call

Working ak8963 mag driver

Functional lps25h driver. Work in progress.

Works well enough to probe and allow sensors task to start.

Added serial port test module

HACK! Get sensors module working

Set crazyflie PWM range

Extend baudrate for Crazyflie's NRF radio

Added dummy tone alarm to allow for init

Added autostart script for Crazyflie

cmake/configs/nuttx_crazyflie_default.cmake

@@ -0,0 +1,152 @@
+include(nuttx/px4_impl_nuttx)
+
+set(CMAKE_TOOLCHAIN_FILE ${CMAKE_SOURCE_DIR}/cmake/toolchains/Toolchain-arm-none-eabi.cmake)
+
+set(config_module_list
+	#
+	# Board support modules
+	#
+	drivers/device
+	drivers/stm32
+	drivers/led
+	drivers/boards/crazyflie
+	drivers/crazyflie
+	drivers/mpu9250
+	drivers/ak8963
+	drivers/lps25h
+	drivers/gps
+	# drivers/pwm_out_sim
+	modules/sensors
+
+	#
+	# System commands
+	#
+	systemcmds/bl_update
+	systemcmds/mixer
+	systemcmds/param
+	systemcmds/perf
+	systemcmds/pwm
+	systemcmds/esc_calib
+	systemcmds/reboot
+	systemcmds/top
+	systemcmds/config
+	systemcmds/nshterm
+	systemcmds/mtd
+	systemcmds/dumpfile
+	systemcmds/ver
+
+	#
+	# General system control
+	#
+	modules/commander
+	modules/navigator
+	modules/mavlink
+	modules/land_detector
+
+	modules/dummy
+
+	#
+	# Estimation modules (EKF/ SO3 / other filters)
+	#
+	# Too high RAM usage due to static allocations
+	# modules/attitude_estimator_ekf
+	modules/attitude_estimator_q
+	modules/ekf_att_pos_estimator
+	modules/position_estimator_inav
+
+	#
+	# Vehicle Control
+	#
+	# modules/segway # XXX Needs GCC 4.7 fix
+	modules/fw_pos_control_l1
+	modules/fw_att_control
+	modules/mc_att_control
+	modules/mc_pos_control
+	modules/vtol_att_control
+
+	#
+	# Logging
+	#
+	modules/sdlog2
+	modules/screen
+
+	#
+	# Library modules
+	#
+	modules/param
+	modules/systemlib
+	modules/systemlib/mixer
+	modules/controllib
+	modules/uORB
+	modules/dataman
+
+	#
+	# Libraries
+	#
+	#lib/mathlib/CMSIS
+	lib/mathlib
+	lib/mathlib/math/filter
+	lib/ecl
+	lib/external_lgpl
+	lib/geo
+	lib/geo_lookup
+	lib/conversion
+	lib/launchdetection
+	lib/terrain_estimation
+	lib/runway_takeoff
+	platforms/nuttx
+
+	# had to add for cmake, not sure why wasn't in original config
+	platforms/common 
+	platforms/nuttx/px4_layer
+
+	#
+	# OBC challenge
+	#
+	modules/bottle_drop
+
+	#
+	# Rover apps
+	#
+	examples/rover_steering_control
+
+	#
+	# Demo apps
+	#
+	#examples/math_demo
+	# Tutorial code from
+	# https://px4.io/dev/px4_simple_app
+	#examples/px4_simple_app
+
+	# Tutorial code from
+	# https://px4.io/dev/daemon
+	#examples/px4_daemon_app
+
+	# Tutorial code from
+	# https://px4.io/dev/debug_values
+	#examples/px4_mavlink_debug
+
+	# Tutorial code from
+	# https://px4.io/dev/example_fixedwing_control
+	#examples/fixedwing_control
+
+	# Hardware test
+	#examples/hwtest
+)
+
+set(config_extra_builtin_cmds
+	serdis
+	sercon
+	)
+
+set(config_extra_libs
+	${CMAKE_SOURCE_DIR}/src/lib/mathlib/CMSIS/libarm_cortexM4lf_math.a
+	)
+
+add_custom_target(sercon)
+set_target_properties(sercon PROPERTIES
+	MAIN "sercon" STACK "2048")
+
+add_custom_target(serdis)
+set_target_properties(serdis PROPERTIES
+	MAIN "serdis" STACK "2048")