drivers: w1 introduce 1-wire api and common code

This commit introduces a new api for the Dallas 1-wire protocol.
The api includes link functions for read and write operations on
bit, byte, and block level, as well as functions to reset and
lock the bus.

The bus configuration is derived from the device tree and can be
queried using w1_slave_count routine.

Signed-off-by: Thomas Stranger <thomas.stranger@outlook.com>