Add PHYTEC Handheld One platform source configuration

[pajoohi]

This PR integrates the platform source configuration and hardware development files for the PHYTEC Handheld One proof-of-concept project.

• Adds tracking files and configurations under the src/phytec-handheld-one/ directory.
• Includes core layout parameters and KiCad schematics.
• Showcases application/HMI capabilities for the AM62P processor within the EVM-Explorer ecosystem.

[Grippy98]

Hey Payam, thanks for the contribution!

To prevent the repo from becoming very large the STP and source files should be hosted externally and only link to it from the main page however.

As example -
https://github.com/TexasInstruments-Sandbox/EVM-Explorer/tree/main/public/evms

[pajoohi]

Hey! thanks for the feedback and that makes sense.
I’ve refactored the PR to align exactly with the standard convention under public/evms/:

Removed Heavy Assets: Completely stripped out the raw CAD databases (.kicad_sch, .kicad_pcb) and the large 3D STEP files (.stp) from the commit history to keep the repository footprint lightweight.

Structured Reference Files: Placed only the user-facing, lightweight documentation—the schematic PDF and the Kitting BOM—inside public/evms/phytec-handheld-one/design/E1/.

External Hosting: The heavy source files and 3D models will remain hosted externally on our dedicated repository (https://github.com/phytec-labs/phytec-handheld-one), which users can easily link out to from this entry.

Let me know if this looks good to go on your end!