common: Comment typo correction
common: Comment typo correction

Corrects the spelling of "functions".
This is more text than the actual diff.

BRANCH=none
TEST=none
BUG=none

Change-Id: Id911bf020d8db9b1d6ad7bfb62d431c5114a64d8
Signed-off-by: Craig Hesling <383db090fd8ef907a606ac8a9eccd2962bc489cf@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1854659
Reviewed-by: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>

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