libnl: minor package fixes

* libnl fails to build with multiple jobs so keep make at -j1
* Multiple libraries are installed so update uninstall target for this

[Peter: remove libnl/libnl-*.* to catch subdir + any new libs in the future]
Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>