Add devm_fpga_bridge_create() which is the managed
version of fpga_bridge_create().

Change current bridge drivers to use
devm_fpga_bridge_create().
Signed-off-by: Alan Tull <atull@kernel.org>
Suggested-by: Federico Vaga <federico.vaga@cern.ch>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>