There are a few TinyUSB CDC functions used for stdio that are currently
replicated across a number of ports. Not surprisingly in a couple of cases
these have started to diverge slightly, with additional features added to
one of them.
This commit consolidates a couple of key shared functions used directly by
TinyUSB based ports, and makes those functions available to all.
Signed-off-by: Andrew Leech <andrew@alelec.net>
c98789a6d8