package/cracklib: properly handle BR2_SYSTEM_ENABLE_NLS=y configurations

Use the TARGET_NLS_DEPENDENCIES and TARGET_NLS_LIBS variables to
correctly handle BR2_SYSTEM_ENABLE_NLS=y configurations.

Fixes:

  http://autobuild.buildroot.net/results/dda70b5b88c75d36c61fbf1cc5fca16ea8414582/



Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>