[roll pigweed] pw_hdlc: Add pw_sys_io HDLC system server

Moves the RPC system server that was copied across multiple targets to
be shared in pw_hdlc to reduce duplication.

Original-Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/106751

https://pigweed.googlesource.com/pigweed/pigweed
pigweed Rolled-Commits: 36b605a10433d6f..e99b5505035da45
Roller-URL: https://ci.chromium.org/b/8805472672963079409
CQ-Do-Not-Cancel-Tryjobs: true
Change-Id: I3b400ce9b4a112c7b054820e3403ddb1feb1f0c6
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/zephyr-integration/+/107336
Commit-Queue: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
Bot-Commit: Pigweed Integration Roller <pigweed-integration-roller@pigweed.google.com.iam.gserviceaccount.com>
1 file changed
tree: 64d3d445cb3b46cde8ae01b9542c46a7baf4fe3d
  1. .gitmodules
  2. test.sh