update-rc.d: support enable/disable options

Add support of enable/disable options, refer
https://manpages.debian.org/wheezy/sysv-rc/update-rc.d.8.en.html



With support of these options, the usr can never change an existing
configuration even after upgrading a package. The program will only
install links if none are present, otherwise, it will keep
the previous configuration.

preinst in update-rc.d.bbclass will delete all the links under
rcrunlevel.d, this behavior now conflicts with enable/disable
options. so remove preinst from the update-rc.d.bbclass

[Yocto 12955]

Signed-off-by: Changqing Li <changqing.li@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>