stdlib: Update AbstractCore `set_simpoint` func

This change:
- Makes this function private.
- Adds better documentation describing the usage.
- Changes the 'init' param to 'board_initialized'

This function really doesn't make much sense to set directly by an
stdlib user. It requires knowing whether or not the the board has been
initialized which is an annoying detail and will cause error if set

The logic of the `init` parameter has been flipped to be
`board_initialized`. This makes it clearer what the parameter is
doing and what it's for.

The documentation for this function has been updated to make it clearer
on how the `board_initialized` parameter should be used correctly.

Change-Id: I567a48df06e6327b38673a2c510065d4334657e2
Reviewed-by: Melissa Jost <>
Reviewed-by: Jason Lowe-Power <>
Maintainer: Bobby Bruce <>
Tested-by: kokoro <>
4 files changed