mb/google/skyrim: Expose SKU and board ID to Chrome OS

Select EC_GOOGLE_CHROMEEC_SKUID and EC_GOOGLE_CHROMEEC_BOARDID to
provide common routine for reading skudid and boardid from Chrome EC.

BUG=b:229052726
TEST=emerge-skyrim coreboot chromeos-bootimage
Check the corresponding directory gets mounted to /run/chromeos-config/v1

Change-Id: I6aff02d29d44e95cd9b9e9485593c81f0d4a4b0e
Signed-off-by: Amanda Huang <amanda_hwang@compal.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64378
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Ian Feng <ian_feng@compal.corp-partner.google.com>
Reviewed-by: Jon Murphy <jpmurphy@google.com>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Frank Wu <frank_wu@compal.corp-partner.google.com>

src/mainboard/google/skyrim/Kconfig

@@ -22,6 +22,8 @@ config BOARD_SPECIFIC_OPTIONS
 	select DRIVERS_WIFI_GENERIC
 	select EC_GOOGLE_CHROMEEC
 	select EC_GOOGLE_CHROMEEC_ESPI
+	select EC_GOOGLE_CHROMEEC_SKUID
+	select EC_GOOGLE_CHROMEEC_BOARDID
 	select ELOG
 	select ELOG_GSMI
 	select FW_CONFIG