tisci: Add support for handling devices

Add support for the following tisci commands for handling devices:
- ti_sci_cmd_enable_device
- ti_sci_cmd_disable_device
- ti_sci_get_device_status

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

k3conf: Initial commit

Add base build infrastructure with the following support:
- Commands: --help, --version
- SoC detection: AM654, J721E
- TISCI version detection using default host

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>