Refactored the i2c driver to parse register values from the device
tree rather than hardcoding them. But still the clocks have to
initialized manually.
The old driver worked well for EEPROMS with the RTEMS EEPROM driver. But
it had problems with a lot of other situations. Although it's not a
direct port, the new driver is heavily modeled after the FreeBSD ti_i2c
driver.
Closes#3764.
