cmd: fs: Add command to list supported fs types

Added command "fstypes" to list supported/included filesystems.

Signed-off-by: Niel Fourie <lusus@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
[trini: Limit to sandbox]
Signed-off-by: Tom Rini <trini@konsulko.com>

cmd/fs.c

@@ -100,3 +100,14 @@ U_BOOT_CMD(
 	"fstype <interface> <dev>:<part> <varname>\n"
 	"- set environment variable to filesystem type\n"
 );
+
+static int do_fstypes_wrapper(struct cmd_tbl *cmdtp, int flag, int argc,
+			      char * const argv[])
+{
+	return do_fs_types(cmdtp, flag, argc, argv);
+}
+
+U_BOOT_CMD(
+	fstypes, 1, 1, do_fstypes_wrapper,
+	"List supported filesystem types", ""
+);