intel/apollolake: Calculate BIOS mmap at runtime

Instead of hard-coding the BIOS region start and end addresses, read
BIOS_BFPREG to determine the base and limit for the mapped BIOS
region.

BUG=chrome-os-partner:54563

Change-Id: Iddd3d4cc945f09e8f147e293bb9144471a6a220d
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/15269
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
3 files changed