common: Move functions for loading from fat/ext2 to fs.h

These are filesystem functions and belong in the filesystem header file.
Move them.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/fat.c b/cmd/fat.c
index 4b9a7ea..50df127 100644
--- a/cmd/fat.c
+++ b/cmd/fat.c
@@ -31,7 +31,7 @@
 	"      and determine its size."
 );
 
-int do_fat_fsload (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+int do_fat_fsload(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	return do_load(cmdtp, flag, argc, argv, FS_TYPE_FAT);
 }