opkg: Set correct info_dir and status_file in opkg.conf

Distros can customize the location of OPKG data using OPKGLIBDIR.  In
OE-Core commit 11f1956c ("package_manager.py: define info_dir and
status_file when OPKGLIBDIR isn't the default"), a fix was applied to
correctly set the info_dir and status_file options relative to
OPKGLIBDIR.

However, as the commit message notes, the opkg.conf file deployed as
part of the opkg package must also be adjusted to correctly reflect the
changed location.  Otherwise, opkg running inside the image cannot find
its data.

Fix this by also setting the info_dir and status_file options in
opkg.conf to the correct location relative to OPKGLIBDIR.

Fixes: 11f1956c ("package_manager.py: define info_dir and status_file when OPKGLIBDIR isn't the default")
Signed-off-by: Harald Seiler <hws@denx.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
(cherry picked from commit adb939ae)
Signed-off-by: Steve Sakoman <steve@sakoman.com>