px4io: reset I2C bus is we lockup for more than 100ms

this happens every 20 minutes or so. It also dumps I2C registers, so
we can see what needs fixing. Here is a typical register dump:

RESETTING line=288
CR1   0x00000401  CR2   0x00000b18
OAR1  0x00000034  OAR2  0x00000000
CCR   0x0000c003  TRISE 0x00000008
SR1   0x00000044  SR2   0x00000002