crossystem: Check for "cros-ec" instead of "mkbp" for *NvStorage
crossystem: Check for "cros-ec" instead of "mkbp" for *NvStorage

This changes the string we look for in the devicetree on ARM
platforms to look for "cros-ec" (DT uses dashes instead of
underscores) instead of "mkbp".

BUG=chrome-os-partner:21097
CQ-DEPEND=CL:273347
BRANCH=none
TEST=with depthcharge patch applied, ran crossystem on newly
booted system and saw VBNV-related variables turn out the same.

Signed-off-by: David Hendricks <3b0deacc4b5357f519084f1ea34bd42bf5d34545@chromium.org>
Change-Id: Iac43f5381327eb878a8d0db606b78bb7bdce816f
Reviewed-on: https://chromium-review.googlesource.com/273391
Commit-Queue: Stefan Reinauer <0ab4fef0c228799b0c44e01c732054569b690b58@chromium.org>
Tested-by: Stefan Reinauer <0ab4fef0c228799b0c44e01c732054569b690b58@chromium.org>
Reviewed-by: Stefan Reinauer <0ab4fef0c228799b0c44e01c732054569b690b58@chromium.org>

coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot,coreboot/vboot