soc/intel/skylake: Clean up bootblock/report_platform.c

This patch ensures that all required information for
pch/mch/igd deviceid and revision available in single
stage and make use of local references.

TEST=Build and boot soraka/eve

Change-Id: I6f7f219536831210750a486ee3b3308d6f285451
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/22756
Reviewed-by: Rizwan Qureshi <rizwan.qureshi@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
4 files changed