USB: Add support for board specific connect/disconnect

Previously the usb driver used #ifs to select a mechanism to
enable and disable the DP pullup.  This doesn't scale well,
especially when the knowledge of how to do this is not known
to the chip specific code, but instead is board specific (as
it is with the STM32F373).

This change uses the build systems ability to build chip family
specific files per build to select the appropriate behavior.
And on the STM32F3 family of parts it just calls out to a board
specific pair of connect/disconnect functions.

Signed-off-by: Anton Staaf <robotboy@chromium.org>

BRANCH=None
BUG=None
TEST=make buildall -j
     Enable console on ryu_p2 and discovery-stm32f072 board
     Verify that it works on both

Change-Id: I976e02fbc7acbb0f85817d7295b26ee9ecab0711
Reviewed-on: https://chromium-review.googlesource.com/229040
Tested-by: Anton Staaf <robotboy@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Commit-Queue: Anton Staaf <robotboy@chromium.org>

0 files changed, 0 insertions, 0 deletions