fs/erofs: add filesystem commands

Add 'ls' and 'load' commands.

Signed-off-by: Huang Jianan <jnhuang95@gmail.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index c13161f..3e7ae7e5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -813,6 +813,7 @@
 M:	Huang Jianan <jnhuang95@gmail.com>
 L:	linux-erofs@lists.ozlabs.org
 S:	Maintained
+F:	cmd/erofs.c
 F:	fs/erofs/
 F:	include/erofs.h