classes/externalsrc: create symlinks for workdir and logs
Auto-create symlinks in the source directory to the work directory
(${WORKDIR}) and logs directory (${T}) so that they are easier for the
user to find. This is particularly useful within the extensible SDK
where the user is less likely to be familiar enough with the structure
of the build system to know where to find these things, but otherwise
they are a useful shortcut for anyone.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
