stage_cache: Disable when APCI S3 is not possible

Don't consume CBMEM for stage cache when we would
never use it.

Change-Id: I606e0457ff3085822554c4041fc56f0d28cc9c2d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/27230
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed