clk: ti: clkctrl: Fix clkdm_clk handling

We need to always call clkdm_clk_enable() and clkdm_clk_disable() even
the clkctrl clock(s) enabled for the domain do not have any gate register
bits. Otherwise clockdomains may never get enabled except when devices get
probed with the legacy "ti,hwmods" devicetree property.

Fixes: 88a17252 ("clk: ti: add support for clkctrl clocks")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>