dt-bindings: clock: lan966x: Add binding includes for lan966x SoC clock IDs

LAN966X supports 14 clock outputs for its peripherals.
This include file is introduced to use identifiers for clocks.

Signed-off-by: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20211103061935.25677-2-kavyasree.kotagiri@microchip.com