MAINTAINERS: fpga: hand off maintainership to Moritz

I'm moving on to a new position and stepping down as FPGA subsystem
maintainer.  Moritz has graciously agreed to take over the
maintainership.
Signed-off-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -6234,7 +6234,6 @@ F:	include/linux/ipmi-fru.h
 K:	fmc_d.*register
 
 FPGA MANAGER FRAMEWORK
-M:	Alan Tull <atull@kernel.org>
 M:	Moritz Fischer <mdf@kernel.org>
 L:	linux-fpga@vger.kernel.org
 S:	Maintained