Add % target to the rules file to work with newer debhelper

debhelper has been updated to 13.3.3 from buster-backports in v2021.

Due to this the below error is seen,

mv debian/tmp/usr/lib/$arch/liblzma.so.* debian/tmp/lib/$arch/; \
dso=$(basename $(readlink debian/tmp/usr/lib/$arch/liblzma.so)); \
ln -s -f /lib/$arch/$dso debian/tmp/usr/lib/$arch/liblzma.so
mv: cannot stat 'debian/tmp/usr/lib/x86_64-linux-gnu/liblzma.so.*': No such file or directory
make[2]: *** [debian/rules:34: override_dh_auto_install] Error 1
make[2]: Leaving directory '/usr/src/packages/BUILD'
make[1]: *** [debian/rules:4: install] Error 2

Add % target to the rules file to work with newer debhelper to fix this issue.

Fixes: https://phabricator.apertis.org/T8834