Command usage cleanup

Remove command name from all command "usage" fields and update
common/command.c to display "name - usage" instead of
just "usage". Also remove newlines from command usage fields.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/common/cmd_license.c b/common/cmd_license.c
index 301af8d..c3c3496 100644
--- a/common/cmd_license.c
+++ b/common/cmd_license.c
@@ -53,7 +53,7 @@
 }
 
 U_BOOT_CMD(license, 1, 1, do_license,
-	   "license - print GPL license text\n",
+	   "print GPL license text",
 	   NULL);
 
 #endif /* CONFIG_CMD_LICENSE */