Just add support for simplebus in syscon_generic.c and nothing else.
Keep ti_scm_syscon.c which "inherit" syscon_generic.c and do TI specific stuffs
- The probe function needs both syscon and simple-bus in compatible field from DTS to match.
- Add clkdev interface to syscon_generic.
- Lower the priority to BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE (otherwise the node will attach to simplebus driver)