su: Don't forcefully add the bin symlink to the installed packages

The LOCAL_MODULE dependency is enough to get it deployed when the
actual binary is built. Adding it to the default modules was leaving
a dangling dead symlink in cases where su isn't bundled (user builds)

Change-Id: I1364cf6537993a8b72bce8c178a7aeec080c9eb3
Merge pull request #5 from CyanogenMod/cm-11.0

su: Don't forcefully add the bin symlink to the installed packages