clk: bcm63xx-gate: switch to dt-bindings definitions

Now that there are header files for each SoC, let's use them in the
bcm63xx-gate controller driver.

Signed-off-by: Álvaro Fernández Rojas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Acked-by: Florian Fainelli <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>

Author: Noltari