package/bbclass: sources are packaged separately from debug.
The configuration variable PACKAGE_DEBUG_SPLIT_STYLE includes
the new mode debug-with-srcpkg that instructs the system to
remove the source files from the debug package but include them in
a separate package with a "-src" suffix in the name.
[YOCTO #9998]
Signed-off-by: Juan M Cruz Alcaraz <juan.m.cruz.alcaraz@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>