Staging: xgifb: Remove LCDA detection in xgifb_probe().

The piece of code that checks for LCDA in xgifb_probe() just checks for some
register values but doesn't really do anything in response to them (the actions
that should be executed are commented).
As nothing is really being done, the code can be safely removed.

Signed-off-by: Miguel Gómez <magomez@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>