refactor(platform-common): adopt odp_client::impl_odp_relay_handler! (Phase 2b)

[dymk]

Summary

Migrates platform/platform-common/src/lib.rs from the deleted
embedded_services::relay::mctp::impl_odp_mctp_relay_handler! macro to
odp_client::impl_odp_relay_handler!, and re-pins all embedded-services
deps to the dymk fork at rev b00c3a7 while PR #11 (canonical ODP wire
format + odp-client crate) awaits upstream merge.

This is Phase 2b of PLAN-006 (cross-repo ODP message-type consolidation).

Why

embedded-services PR OpenDevicePartnership#11 deleted embedded_services/src/relay/mctp/ and
moved the relay-handler macro into a new odp-client crate. Any consumer
that bumps its embedded-services pin past that PR will fail to build
until this migration lands. Branch dymk/dev-qemu-mctp-serial-medium
previously bumped branch = "v0.2.0" → branch = "main" (commit
already squashed during this rebase as it was applied upstream as OpenDevicePartnership#23),
so this PR is the natural follow-up.

Changes

File	Change
platform/platform-common/src/lib.rs	macro path swap (1 line). Argument grammar is unchanged.
platform/platform-common/Cargo.toml	add odp-client direct dep + [patch] block
platform/{dev-qemu,dev-imxrt,dev-npcx,dev-mcxa,dev-mec}/Cargo.toml	add identical [patch] block (14 entries) re-routing embedded-services deps to dymk fork rev b00c3a7
platform/*/Cargo.lock	regenerated against patched sources

Pin reversion plan

Once OpenDevicePartnership/embedded-services PR OpenDevicePartnership#11 merges to upstream
main, a follow-up will delete the 6 [patch.\"https://github.com/OpenDevicePartnership/embedded-services\"]
blocks and cargo update will re-resolve to upstream.

Validation

All 5 CI-matrix platforms pass cargo clippy --locked and
cargo fmt --check:

• platform-common / dev-qemu / dev-imxrt / dev-npcx / dev-mcxa

Also verified:

• dev-qemu builds a 6.3 MB riscv32imac-unknown-none-elf ELF
• dev-mec (not in CI matrix) builds cleanly

A pre-existing clippy::clone_on_copy finding in
platform-common/src/mock/battery.rs:35 is gated behind
--all-features --all-targets, which is NOT part of CI scope
(CI runs default-features clippy --locked per platform). Reproduces
unchanged on origin/main. Out of scope for this PR.

Parallel-safe

Independent of Phase 2 (dymk/odp-secure-services#3) and Phase 3
(dymk/odp-platform-common). All three feed into the
odp-platform-qemu-sbsa integration PR (Phase 4).

[github-actions]

Cargo Vet Audit Failed

cargo vet has failed for one or more platforms in this PR. See the cargo-vet workflow run for which platform(s) failed, and run cargo vet --locked locally from platform/<dev-*>/ to reproduce.
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[dymk]

Superseded by a fresh-eyes minimal approach. The serial-medium idea here is right, but this branch bundles it with the odp_client adoption (parked — see embedded-services #875). The EC dev-qemu MctpSerialMedium change is small (~12 lines of main.rs) and will be rewritten fresh against current upstream main using the existing impl_odp_mctp_relay_handler! macro. Closing; branch retained as a reference model.