staging.bbclass: Make it easier to define which dirs to stage
The directories that should be staged in the sysroot are now specified
in the SYSROOT_DIRS variable. Extra directories that should be staged
for native are specified in SYSROOT_DIRS_NATIVE. Finally, directories
that should not be staged are specified in SYSROOT_DIRS_BLACKLIST.
This also removes the sysroot_stage_libdir() function as it is no
longer used (it was just a wrapper for sysroot_stage_dir()).
Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
