octopus: enable CONFIG_CMD_CHARGEN
octopus: enable CONFIG_CMD_CHARGEN

BUG=b:1568477297
BRANCH=octopus
TEST=On firmware-octopus-11297.83.B, cherry-picked this patch along
with related preceding patches, and tested the built image on fleex.

Cq-Depend: chromium:1679710
Cq-Depend: chromium:1554198
Cq-Depend: chromium:1688134
Cq-Depend: chromium:2080933
Cq-Depend: chromium:2217112
Change-Id: I7bc4269d2e2799160ef3dfd96f9a94c8a4636902
Signed-off-by: Namyoon Woo <e8732cefb861f07768f47df788a8e8eb75efc09a@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2236872
Reviewed-by: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>
Commit-Queue: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>

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