bus: ti-sysc: Build driver for TI K3 SoCs

Allow building ti-sysc also for K3 SoCs. This allows configuring the wkup
domain devices for SYSCONFIG register wake-up events in a generic way.

As this is an interconnect level driver, default to built-in on K3 SoCs
to probe the devices connected to the wkup domain like gpio, uart and
timers.

Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>