[dpdk-stable] [PATCH v3 0/6] power: fix make build for power apps

[David Hunt]

The guest channel message definitions and functions in guest_channel.h
are needed by applications and need to be made public.

This worked pre-20.11, but now with all the meson/ninja changes, making
these apps externally no longer works. To fix, we need to move the
header file with the API definitions for the channel commands public,
and rename the functions accordingly.

The main change is to rename channel_commands.h to
rte_power_guest_channel.h so that it gets picked up by the installer
and copied to /usr/local/include. Other changes include renaming #defines
to have RTE_ at the beginning instead of CPU_. Finally we refactor the
code to work with those changes.

---
v2 changes
  - re-worked from monolithic patch to a 6 patch patchset for easier review
v3 changes
  - Ensure both functions added to the API are tagged as experimental