This adds entries for I2C8-10 to giant switch statement in
clock_get_periph_rate(). It also eliminates the I2C peripheral's
usage of clk_bit_info since it's confusing and error-prone.
BUG=chrome-os-partner:19420
BRANCH=none
TEST=TODO...
Change-Id: I4b006c034575e6bd1f4722503668b9a142020eb5
Reviewed-on: https://gerrit.chromium.org/gerrit/58782
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: David Hendricks <dhendrix@chromium.org>
Tested-by: David Hendricks <dhendrix@chromium.org>