AGESA: Implement POSTCAR_STAGE

Move all boards that have moved away from AGESA_LEGACY_WRAPPER
or BINARYPI_LEGACY_WRAPPER to use POSTCAR_STAGE.

We use POSTCAR_STAGE as a conditional in CAR teardown to tell
our MTRR setup is prepared such that invalidation without
writeback is a valid operation.

Change-Id: I3f4e2170054bdb84c72d2f7c956f8d51a6d7f0ca
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/21384
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
22 files changed