arm64: dts: ti: k3-j784s4: Add bootph-* properties

The following nodes are being used in the bootloaders. Adds bootph-*
properties to the leaf nodes to enable bootloaders to utilise them.

Following adds bootph-* to
- secure_proxy_sa3/secure_proxy_main mboxes for communication with
  System Controller
- wkup_vtm for enabling Adaptive voltage scaling(AVS) support

Signed-off-by: Manorit Chawdhry <m-chawdhry@ti.com>
Link: https://lore.kernel.org/r/20241024-b4-upstream-bootph-all-v6-3-2af90e3a4fe7@ti.com


Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>