Move drirc.d access to dri-common abstraction
Commit b5be5964 added ability to read /usr/share/drirc.d/ directory to mesa abstraction.
This seems to be a mistake, as it was noted that not all GUI applications, that need access to drirc.d, also need whole mesa-related rules (including writing caches).
Move /usr/share/drirc.d/ access to different abstraction. This is not a breaking change, because any GUI application will have included X abstraction already, and in the end result - dri-common abstraction too.