dev_gmsl: [RSDEV-13503][RSDEV-13505][D585][GMSL] Add tunnel RGB-right on VC4

[polejoe]

Summary

Port the D5x tunnel-mode RGB-right support from #576 onto dev_gmsl_merge.

• add the D585 2C RGB-right control path and expose it on CSI VC4
• keep the existing VC0 Depth, VC1 RGB, VC2 IR, and VC3 IMU mapping unchanged
• gate RGB-right by the D585 2C product PID so 3C products do not expose or fall back to a second RGB stream
• enforce the 2C image-stream ceiling of 30 FPS in the kernel-enumerated profiles
• allow the MAX96724 Link-A tunnel to share one physical pipe across logical VCs with reference-counted lifetime
• append the VC4 VI/NVCSI endpoint only in the D5x FG24 tunnel overlay

The change does not modify the MAX96712 path, pixel-mode overlays, or generic VI/NVCSI implementation.

Compatibility

The branch is based directly on dev_gmsl_merge. A three-way merge check against PR #592 reports a clean automatic merge; stacking is not required.

On the Jetson67 3C device (PID 0x0c08), the deployed driver rejected the DUALRGB_RIGHT instance with -ENODEV and preserved the existing node mapping:

Stream	VC	Live node
Depth	0	/dev/video0
Depth metadata	0	/dev/video1
RGB	1	/dev/video2
RGB metadata	1	/dev/video3
IR	2	/dev/video4
IR metadata	2	/dev/video5
IMU	3	/dev/video6

For D585 2C, RGB-right is added on VC4 after the existing channels. Numeric /dev/videoN values are registration-order details rather than a stable userspace ABI; userspace should resolve the stable RealSense links or media entities.

Validation

• JP6.2.2 full clean build passed for kernel 5.15.185-tegra
• full rootfs package built from commit 6ca0568
• deployed to Jetson67 and rebooted successfully
• orin-gmsl verify --require-loaded passed
• installed Image, DTB, D5x DTBO, and module hashes match the package
• d4xx, max96717, and max96724 loaded with matching vermagic
• 3C live probe registered only Depth, RGB, IR, and IMU; RGB-right was not exposed