core-image-minimal: do not remove packaging files in the rootfs postprocess

core-image-minimal: do not remove packaging files in the rootfs postprocess

Since the removal of PM's meta-data was moved in image.bbclass, after
rootfs_*_do_rootfs() runs, there's no need to remove the files in rootfs
postprocess stage. Also, if the meta-data is removed then there's no way
we can save the postinstalls to /etc/(deb|ipk)-postinsts later.

For RPM, it doesn't really matter since the postinstalls are saved to
/etc/rpm-postinsts as soon as the postinstall fails.

[YOCTO #4484]

(From OE-Core rev: aac8a59216819759d6b97bc30a7c717dbee7060a)

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>