arm64: dts: ti: k3-j7200-mcu-wakeup: Add SA2UL node

J7200 has an instance of SA2UL in the MCU domain.
Add DT node for the same.

The device is marked TI_SCI_PD_SHARED as parts of this IP are also
shared with the security co-processor and OP-TEE.

The RNG node is added but marked disabled as it is firewalled off for
exclusive use by OP-TEE. Any access to this device from Linux will
result in firewall errors. We add the node for completeness of the
hardware description.

Signed-off-by: Andrew Davis <afd@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Reviewed-by: Jayesh Choudhary <j-choudhary@ti.com>
Link: https://lore.kernel.org/r/20220823001136.10944-4-afd@ti.com