linux-imx

mei: make module referencing local to the bus.c

Module reference counting is relevant only to the
mei client devices. Make the implementation clean
and move it to bus.c

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>