Add do_disable_clocks() to disable clock domains and module clocks.
These clocks are enabled using do_enable_clocks().

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Vignesh R <vigneshr@ti.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>