cifs-utils: add PACKAGECONFIG for pam

* otherwise there are unpackaged files:
ERROR: QA Issue: cifs-utils: Files/directories were installed but not shipped in any package:
  /usr/lib/security
  /usr/lib/security/pam_cifscreds.so
  /usr/lib/security/.debug
  /usr/lib/security/.debug/pam_cifscreds.so
Please set FILES such that these items are packaged. Alternatively if they are unneeded, avoid installing them or delete them within do_install.
cifs-utils: 4 installed and not shipped files. [installed-vs-shipped]

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>