bus: ti: add minimal sysc interconnect target driver

We can handle the sysc interconnect target module in a generic way for
many TI SoCs. Initially let's just enable domain clocks before the
children are probed.

The code is loosely based on the drivers/bus/ti-sysc.c of the Linux
kernel version 5.9-rc7.
For DT binding details see:
- Documentation/devicetree/bindings/bus/ti-sysc.txt

Signed-off-by: Dario Binacchi <dariobin@libero.it>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index fbe9087..6b5235e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -799,6 +799,7 @@
 	select SPL_BOARD_INIT if SPL
 	select SPL_STACK_R if SPL
 	select SUPPORT_SPL
+	imply TI_SYSC if DM && OF_CONTROL
 	imply FIT
 
 config ARCH_MESON