chromeec: lpc: Add variant MEC IO

MEC cannot access memmap-range data directly though LPC and instead must
access through its EMI unit.

BUG=chrome-os-partner:38224
TEST=Verify host command functionality on glower.
BRANCH=None

Change-Id: If98d425014a894ddeafad4268f92af5860878522
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 58ed3c50ab97ca1e172d5cdc00f4cd8e069e565c
Original-Change-Id: I32b897836d28ef4f3b3aa5f81b9023f2ceb629c8
Original-Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/263611
Original-Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/9910
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
5 files changed