CBMEM: Always select CAR_MIGRATION

If romstage does not make cbmem_initialize() call, linker should
optimize the code for CAR migration away.

This simplifies design of CBMEM console by a considerable amount.
As console buffer is now migrated within cbmem_initialize() call there
is no longer need for cbmemc_reinit() call made at end of romstage.

Change-Id: I8675ecaafb641fa02675e9ba3f374caa8e240f1d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3916
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/lib/hardwaremain.c

@@ -177,7 +177,7 @@ static boot_state_t bs_post_device(void *arg)
 {
 	timestamp_add_now(TS_DEVICE_DONE);
 
-	timestamp_sync();
+	timestamp_reinit();
 
 	return BS_OS_RESUME_CHECK;
 }