archiver.bbclass: move a few code to copyleft_compliance.bbclass
Move the code which is only used by copyleft_compliance.bbclass from
archiver.bbclassc, and remove the "inherit archiver" from
copyleft_compliance.bbclass.
The archiver.bbclass is used for archiving various types of sources, but
the copyleft_compliance.bbclass is used for analysing the license, they
don't have much relationships.
[YOCTO #4986]
[YOCTO #5113]
Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
