FMUv2: fixed UART3 flow control pins

FMUv2: fixed UART3 flow control pins

FMUv2: push SPI2 GPIO speed up to 50MHz as well

hmc5883: much faster calibration code with bug fixes

this fixes two bugs in "hmc5883 calibrate" and also makes it much
faster, so it can be run on every boot. It now uses the correct 2.5Ga
range when calibrating, and fixes the expected values for X/Y/Z axes

The basic calibration approach is similar to the APM2 driver, waiting
for 10 good samples after discarding some initial samples. That allows
the calibration to run fast enough that it can be done on every boot
without causing too much boot delay.

hmc5883: much faster calibration code with bug fixes

this fixes two bugs in "hmc5883 calibrate" and also makes it much
faster, so it can be run on every boot. It now uses the correct 2.5Ga
range when calibrating, and fixes the expected values for X/Y/Z axes

The basic calibration approach is similar to the APM2 driver, waiting
for 10 good samples after discarding some initial samples. That allows
the calibration to run fast enough that it can be done on every boot
without causing too much boot delay.

ms5611: give cleaner SPI traces

this makes logic traces cleaner by zeroing extra bytes written

lsm303d: always log first ARB and REG values

Test flown June version of codebase