Zephyr restructured its includes in v2.0 and removed compatibility shims
after two releases in commit 1342dadc365ee22199e51779185899ddf7478686.
Updates include paths in MicroPython accordingly to fix build errors in
the zephyr port.
These changes are compatible with Zephyr v2.0 and later.
Adds support for hardware i2c to the zephyr port. Similar to other ports
such as stm32 and nrf, we only implement the i2c protocol functions
(readfrom and writeto) and defer memory operations (readfrom_mem,
readfrom_mem_into, and writeto_mem) to the software i2c implementation.
This may need to change in the future because zephyr is considering
deprecating its i2c_transfer function in favor of i2c_write_read; in this
case we would probably want to implement the memory operations directly
using i2c_write_read.
Tested with the accelerometer on frdm_k64f and bbc_microbit boards.
