arm: mvebu: crs3xx-98dx3236: Add a maintainer

Add Luka Perkov to CRS3xx-98DX3236 MAINTAINERS.
Signed-off-by: NLuka Kovacic <luka.kovacic@sartura.hr>
Cc: Luka Perkov <luka.perkov@sartura.hr>
Cc: Jakov Petrina <jakov.petrina@sartura.hr>
Reviewed-by: NStefan Roese <sr@denx.de>

board/mikrotik/crs3xx-98dx3236/MAINTAINERS

 CRS3XX-98DX3236 BOARD
 M:	Luka Kovacic <luka.kovacic@sartura.hr>
+M:	Luka Perkov <luka.perkov@sartura.hr>
 S:	Maintained
 F:	board/mikrotik/crs3xx-98dx3236/
 F:	include/configs/crs3xx-98dx3236.h