util-linux: fix the su and runuser packages

util-linux: fix the su and runuser packages

The packages get an automatic RDEPENDS via shlibs, no
need to explicitly state it, so we can drop those
useless explicit assignments.

su is moved into ${base_bindir} in do_install(), so
because of a mismatched FILES specification su is
actually packaged into the main package at the moment,
not into the -su package as likely originally intended.

runuser needs the pam configuration files, so they should
be in the -runuser package, not in the main package.

While fixing this, we can simplify the update alternatives
processing for su.

[YOCTO #13058]

(From OE-Core rev: d8f4ffdc6db5484de97186586a7f39da32205c7b)

Signed-off-by: André Draszik <andre.draszik@jci.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>