guybrush: a0z1380 set vbus_source_current_limit
guybrush: a0z1380 set vbus_source_current_limit

Fill in vbus_source_current_limit stub.
Add missing io expander configuration.

BUG=None
BRANCH=None
TEST=Build

Signed-off-by: Rob Barnes <3ced0940a2329ce70499686f01d3d60685ec66ed@google.com>
Change-Id: I2e196333ad607297e33a72b64839f5485e42f909
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2611818
Commit-Queue: Denis Brockus <6b21e8190fb5e373363fb95271367073a16474ef@chromium.org>
Reviewed-by: Denis Brockus <6b21e8190fb5e373363fb95271367073a16474ef@chromium.org>
Reviewed-by: Diana Z <cb2016afc7183e5356c690dc63b4ba817470501a@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec