multilib.bbclass: Fix renaming logic for "FILES_", "RDEPENDS_", etc

multilib.bbclass: Fix renaming logic for "FILES_", "RDEPENDS_", etc

In the orignal logic, the renaming will not work for "FILES_" if defined
variables as:

PACKAGES = "${PN}"
FILES_abc = "/usr/include/abc.h"

It is because ${PN} is "lib64-abc" so it will not be contained in
pkgrename.

This commit enumerates all element in PACKAGES, getting the original
packages and multilib packages, then doing renaming for "FILES_",
"RDEPENDS_", etc. This fixes a lot of missing files and incorrect
dependencies.

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>