grunt: Send sensor MKBP events using host event
grunt: Send sensor MKBP events using host event

Add CONFIG_MKBP_EVENT and CONFIG_MKBP_USE_HOST_EVENT
to send sensor events to AP.

BUG=b:77342604
BRANCH=none
TEST=view sensors in AIDA64 Android app in ARC++

Change-Id: I3687072903d251bccb2cdf7670b0780a906dd22d
Signed-off-by: Edward Hill <db1406b34e091703092b6b136bdfeb2c8125fc0e@chromium.org>
Signed-off-by: Gwendal Grignou <190c5a5edfcf62e0246559bf31fa7548674de3ad@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1012457

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