* [WIP] i2c_spi_buses: add '-q' for quiet startup flag
And enable for optional board sensors.
* ROMFS: rc.sensors try starting all optional I2C sensors quietly
Co-authored-by: Daniel Agar <daniel@agar.ca>
instead of a static per-driver array.
Reduces BSS RAM usage by a couple of 100 Bytes (linear increase with num
drivers).
Downsides:
- a bit more runtime overhead
- less isolation, locking required
- a bit more complex