fs: Add command to retrieve the filesystem type

New command to determine the filesystem type of a given partition.
Optionally stores the filesystem type in a environment variable.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Reviewed-by: Stephen Warren <swarren@nvidia.com>

include/fs.h

@@ -109,4 +109,10 @@ int do_save(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
 int do_fs_uuid(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[],
 		int fstype);
 
+/*
+ * Determine the type of the specified filesystem and print it. Optionally it is
+ * possible to store the type directly in env.
+ */
+int do_fs_type(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
+
 #endif /* _FS_H */