gec_i2c: only descend up to 2 levels in sysfs when searching for bus

Snow's I2C sysfs hierarchy can get very deep and cause the scanft()
algorithm to slow down substantially. We only need to go 2-deep in
order to find the info we're looking for.

BRANCH=snow
BUG=chrome-os-partner:16152
TEST=tested sysfs parsing for snow i2c passthru device

Change-Id: I8067a4d2a6e21ac6fdfeb3b0f2d1b98e56206e74
Reviewed-on: https://gerrit.chromium.org/gerrit/38252
Commit-Ready: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
1 file changed