From: Ville Syrjälä <ville.syrjala@linux.intel.com>

We may want to poke at various other connector attributes
via sysfs/debugfs. Generalize the existing the force_connectors
mechamisn to handle arbitrary attributes.

v2: Fix connector_attr_alloc()
    Set c->value before using it

Cc: Kunal Joshi <kunal1.joshi@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>