This commit removes the Multipurpose (MP) frame format support
(`OPENTHREAD_CONFIG_MAC_MULTIPURPOSE_FRAME`) and associated
wake-up frame handling.
Multipurpose frame support was originally added as a provisional and
experimental solution for the Wakeup Coordinator / Wake-up End Device
(WED) wake mechanism. However, updated Thread specification designs
decided against using the Multipurpose frame format for wake frames.
Removing this now obsolete MP frame logic cleans up and simplifies
MAC frame parsing and generation ahead of implementing the updated
wake mechanism.
Key changes:
- Removes `OPENTHREAD_CONFIG_MAC_MULTIPURPOSE_FRAME` from `mac.h` and
adds an `#error` check in `openthread-core-config-check.h`.
- Simplifies `Mac::Frame` control field (FCF) parsing and helper methods
by removing MP-specific frame handling and template helpers.
- Replaces legacy MP wake-up frame helpers in `mac_frame.cpp` with
temporary placeholder stubs.
- Cleans up unit tests in `test_mac_frame.cpp` related to MP frame
format.
- Removes the now obsolete `v1_5-cli-p2p-link.exp` test.
Abtin Keshavarzian
a56a79bcb7