staging: olpc_dcon: move more variables into dcon_priv

This moves dcon_source and dcon_pending into the dcon_priv struct.

Because these variables are used by the IRQ handler (which is
registered in the model-specific callbacks), we end up needing
to move dcon_priv into olpc_dcon.h.  This also changes the IRQ
registration to use the dcon_priv pointer as dev_id, instead of
dcon_driver.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>