feat(ti): synchronize access to secure proxy threads

When communicating with the system controller over secure proxy we clear
a thread, write our message, then wait for a response. This must not be
interrupted by a different transfer on the same thread. Take a lock
during this sequence to prevent contention.

Signed-off-by: Andrew Davis <afd@ti.com>
Change-Id: I7789f017fde7180ab6b4ac07458464b967c8e580
1 file changed