MAINTAINERS: add maintainer information for z3fold

Add the maintainer information for the z3fold compressed page allocator.
Also Add myself as a reviewer.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Miaohe Lin <[e-mail]>
Cc: Vitaly Wool <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

MAINTAINERS

···
 S:	Maintained
 F:	mm/zbud.c
 
+Z3FOLD COMPRESSED PAGE ALLOCATOR
+M:	Vitaly Wool <[e-mail]>
+R:	Miaohe Lin <[e-mail]>
+L:	[e-mail]
+S:	Maintained
+F:	mm/z3fold.c
+
 ZD1211RW WIRELESS DRIVER
 M:	Ulrich Kunitz <[e-mail]>
 L:	[e-mail]