uboot-phytec

buildman: Fix up a few code inconsistencies in toolchain.py

Normally we use a single quote for strings unless there is a reason not to
(such as an embedded single quote). Fix a few counter-examples in this file.
Also add a missing function-argument comment.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>