My previous implementation of ti_clkctrl with gate subclocks wasnt that good.
- Change to use proper gate (sys/dev/extres/clk/clk_gate.c) instead of a special flag in ti_clk_clkctrl.c
- Use constants from devicetree definitions.
- add comments there to find the clocks in the TRM (&dts labels)
AM335x also got subclocks in TRM CM_WKUP_DEBUGSS_CLKCTRL 18.104.22.168.6 but i silently ignore these subclocks until AM572x support are done.