zephyr: Add a fake CONFIG_CRC8
zephyr: Add a fake CONFIG_CRC8

Add this to reduce the CONFIG delta between Zephyr and ECOS. It is not
actually used with Zephyr.

BUG=b:178124020
BRANCH=none
TEST=none

Signed-off-by: Simon Glass <c00b0378376498bd9cd974c388df8854c0131d27@chromium.org>
Change-Id: Iaab56c21b7c5eee8a56d6fe4443feaa50baa8774
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2678925
Reviewed-by: Jack Rosenthal <d3f605bef1867f59845d4ce6e4f83b8dc9e4e0ae@chromium.org>

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