This adds a new function that can be use to apply USB EQ settings
to the mux. It currently only exposes the Tx and Rx channel
loss compensation.
BUG=chrome-os-partner:47074
BRANCH=none
TEST=build and boot on chell
Change-Id: I1ec83cdcbb17da8e7289e6633509b64f01b14348
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/313747
Reviewed-by: Shawn N <shawnn@chromium.org>