- starts requirements for PX4 modules (hrt, param, etc)

 - can be reenabled after #11256 is merged

 * We have RAM problems and can't afford 4 mavlink instances. This only adds logic the rc.board for the fmu-v4 that only has an effect for SYS_AUTOSTART = 4250 (TealOne airframe).

Fixed ICM20948 magnetometer only option.
Specified bus for internal mpu9250 on Pixhawk 2.1 to avoid premature detection of
other device.

- fixes #11009

Not all boards have an SD card.

This is a *breaking* change and requires a bootloader change.

Instead of using the define __PX4_POSIX_SITL it makes more sense to have
a define just to determine if the lockstep scheduler should be used.

The new board config changed everything, so I needed to move the
lockstep_scheduler repo.

This is a step towards isolating time from the system.

This updating of the driver setting is for EMI issue with GPS and FCC.
   With this setting the clock is sinusoidal

   N.B. sd_bench fails on SanDISK HC, but Passes SanDISK **HC1** and
   Kingston cards.

   ****Use HC1 or Kingston cards!***

   Testing done on SanDISK HC all failed sd_bench with Drive/Slew other
   than default and _PIN_OUTPUT_FAST|_PIN_OUTPUT_HIGHDRIVE

	_PIN_OUTPUT_FAST|_PIN_OUTPUT_HIGHDRIVE    Square noisy, pass SanDISK HC
        _PIN_OUTPUT_FAST|_PIN_OUTPUT_LOWDRIVE     Square noisy, pass SanDISK HC
        _PIN_OUTPUT_HIGHDRIVE|_PIN_OUTPUT_SLOW    sinusoidal fail SanDISK HC, pass SanDISK HC1
        _PIN_OUTPUT_LOWDRIVE |_PIN_OUTPUT_SLOW    sinusoidal fail SanDISK HC, pass SanDISK HC1
                              _PIN_OUTPUT_SLOW    sinusoidal fail SanDISK HC, pass SanDISK HC1

_Stof, bsearch, param_find_changed

* added a parameter for enabled the smart battery
* start tel1 and tel2 at 921600 and max rate
* turned up the max tx rate on mavlink streams for telem1 and telem2
* turned off mavlink stream for tel1 in 4250_teal. This is connected to TX1 FTDI UART and has issues.
* moved check to 4250 board ID to start mpu9250s for Teal airframe into fmuv4 rc.board.

 - these flags were accumlating on top of each other anytime cmake had to reconfigure