arm64: dts: ti: k3-j721s2: Add PCIe ctrl node to scm_conf region

arm64: dts: ti: k3-j721s2: Add PCIe ctrl node to scm_conf region

This region is used for controlling the function of the PCIe IP. It is
compatible with "ti,j784s4-pcie-ctrl", add this here and use it with
the PCIe node.

Signed-off-by: Andrew Davis <afd@ti.com>
[j-choudhary@ti.com: Add changes to k3-am68-sk-base-board-pcie1-ep.dtso]
Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
Reviewed-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Link: https://lore.kernel.org/r/20250402113201.151195-5-j-choudhary@ti.com
Signed-off-by: Nishanth Menon <nm@ti.com>