MAINTAINERS: Make Yu Kuai co-maintainer of md/raid subsystem

In the past couple years, Yu Kuai has been making solid contributions
to md/raid subsystem. Make Yu Kuai a co-maintainer.

Reviewed-by: Yu Kuai <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Song Liu <[email protected]>

Author: liu-song-6

MAINTAINERS

@@ -21303,7 +21303,7 @@ F:	include/linux/property.h
 
 SOFTWARE RAID (Multiple Disks) SUPPORT
 M:	Song Liu <[email protected]>
-R:	Yu Kuai <[email protected]>
+M:	Yu Kuai <[email protected]>
 L:	[email protected]
 S:	Supported
 Q:	https://patchwork.kernel.org/project/linux-raid/list/