arm64: dts: ti: k3-*: Rename the TI-SCI clocks node name

We currently use clocks as the node name for the node representing
TI-SCI clock nodes. This is better renamed to being clock-controller
as that is a better representative of the system controller function
as a clock controller for the SoC.

Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Tero Kristo <kristo@kernel.org>
Link: https://lore.kernel.org/r/20210510145033.7426-2-nm@ti.com