rootfs.py, sdk.py: adjust/create the wrappers for creating installed packages list
Since we created a new PkgsList object that will deal with listing the
installed packages in a rootfs, use the new class both for images and
SDKs in the wrapper functions.
The old list_installed_packages() wrapper listed only the packages inside
an image rootfs. It didn't deal with target/host SDK rootfs's.
Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
