MAINTAINERS: add myself as reviewer for SquashFS

I also followed the development of the SquashFS support in U-Boot
as part of Joao Marcos internship, so I would also appreciate receiving
new contributions and bug reports related to this topic.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index fdbfd2b..7e46470 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -984,6 +984,7 @@
 SQUASHFS
 M:	Joao Marcos Costa <joaomarcos.costa@bootlin.com>
 R:	Thomas Petazzoni <thomas.petazzoni@bootlin.com>
+R:	Miquel Raynal <miquel.raynal@bootlin.com>
 S:	Maintained
 F:	fs/squashfs/
 F:	include/sqfs.h