clk: renesas: r9a06g032: Add clock domain support

There are several clocks on the r9a06g032 which are currently not
enabled in their drivers that can be delegated to clock domain system
for power management. Therefore add support for clock domain
functionality to the r9a06g032 clock driver.
Signed-off-by: Gareth Williams <gareth.williams.jx@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>