Merge FMUv3 into FMUv2

[dagar]

This is a fix for the pixhawk mini which needs to use the px4fmu-v2_default binary due to lacking bootloader versioning.

FMUv3 was a superset of FMUv2 that used the full 2MB flash and added runtime version detection to handle various board differences in the pixhawk 2 cube and pixhawk mini.

This PR combines FMUv3 into FMUv2 with the only difference being the linker script used by FMUv3 and PX4 module list.

[dagar]

I've done some simple bench testing with an original pixhawk (px4fmu-v2) and pixhawk cube 2.1 (px4fmu-v3). The version is correctly detected and all sensors are present with correct external detection.

@PX4TestFlights @LorenzMeier @bkueng could someone thoroughly checkout a pixhawk mini with this branch? Flash px4fmu-v2, reset all params, and recalibrate. From that ulog we can verify everything.

[r0gelion]

@dagar

I'm getting this error when trying to compile px4fmu-v2

running cmake 3.7.1 in mac os sierra 10.12.6

[bkueng]

Tested on a pixhawk mini: compared master with v3 against this branch with v2 target: I don't have boot output, but bench testing checks out.
I looked at top, ls /dev, sensors status (it does not seem to have an internal mag), then attached a gps, and the mag got detected. Did a param reset & full calibration.

ver all:

nsh> ver all
HW arch: PX4FMU_V2
HW type: V2M
HW version: 0x0009000A
HW revision: 0x00000000
FW git-hash: a4ac735791cfa03b15c4bec016b7165734d8e37e
FW version: 1.7.0 0 (17235968)
OS: NuttX
OS version: Release 7.21.0 (118817023)
OS git-hash: 85a88c073130c0f9dd83af0a67e61c445ab0b3fa
Build datetime: Nov 23 2017 18:00:22
Build uri: localhost
Toolchain: GNU GCC, 5.4.1 20160919 (release) [ARM/embedded-5-branch revision 240496]
MFGUID: 333735383335510800480042
MCU: STM32F42x, rev. 3
UID: 480042:33355108:33373538

[santiago3dr]

pixhawk mini bench test after flash and full reset; all sensor calibrations went through without errors
https://logs.px4.io/plot_app?log=728eb1e2-7e1c-4f2b-9f34-6c97ef2f579e

[santiago3dr]

ran full setup on a different pixhawk mini
calibrations:
https://logs.px4.io/plot_app?log=8511764b-6b29-49c0-8b2e-62312963789d
indoor flight test:
https://logs.px4.io/plot_app?log=074589a2-6696-49c8-9287-114ffbced108
full outdoor flight test:
https://logs.px4.io/plot_app?log=ac5c287a-d7d6-46da-8d85-bc7ef268128c

no errors, flew well; all tested modes worked as expected

[hamishwillee]

@dagar

Removed ground vehicle controllers from px4fmu-v2 to make room.

Saw above in email. Does that mean you can't do rover type vehicle on Pixhawk etc any more? Do we need to communicate somehow to users either how they add them back (ideally) or what FMU versions will work?

[dagar]

@hamishwillee good catch, but I backed that out after freeing up some extra space here. #8344