devtool: ide-sdk recommend DEBUG_BUILD

devtool: ide-sdk recommend DEBUG_BUILD

The debug_build_config function was never called. Compiling with debug
optimized compiler flags was not working. Even with the
--debug-build-config flag set, the build configuration from the recipe
was used.

The devtool ide-sdk --debug-build-config approach didn't work very well
anyway. The problem is that changing the bbappend file doesn't work
while bitbake uses the bbappend file. As a workaround, it would be
possible to parse the recipe, get DEBUG_BUILD and the path to the append
file, exit tinfoil, change the bbappend file, reopen tinfoil and do what
ide-sdk is supposed to do. Such an implementation would be complicated
and slow.
Therefore, the code that was originally supposed to implement this is
removed from ide-sdk and the new --debug-build function of devtool
modify is used instead. Additionally, a hint should be given on how to
manually add DEBUG_BUILD = '1' to bbappend.

This is compatible with the VSCode Bitbake plug-in, which does not
support this parameter anyway.

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>