fpga: bridge: kernel-doc fixes

Fix the following warnings when documentation is built:

./drivers/fpga/fpga-bridge.c:143: warning: Function parameter or
member 'info' not described in 'fpga_bridge_get'

./drivers/fpga/fpga-bridge.c:1: warning: no structured comments found

Signed-off-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>