dt-bindings: Add generic bindings for PECI

Add device tree bindings for the PECI controller.

Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20220208153639.255278-2-iwona.winiarska@intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>