dt-bindings: clock: Add NIC and ETHERNET bindings for Actions S500 SoC

Add the missing NIC and ETHERNET clock bindings constants for Actions
Semi Owl S500 SoC.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1d0902cf073f76a1a602410061481ccb3fc36a72.1623354574.git.cristian.ciocaltea@gmail.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>