[coreboot] [coreboot - Cleanup #308] (New) Deal with walkcbfs_asm

Issue #308 has been reported by Patrick Georgi.

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Cleanup #308: Deal with walkcbfs_asm
https://ticket.coreboot.org/issues/308

* Author: Patrick Georgi
* Status: New
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
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To remove the CBFS master header, walkcbfs_asm needs to either be made aware of fmap or removed.

Current users (as determined by Arthur):
 - Updating microcode before CAR on systems that don't do µcode updates through FIT
 - Finding FSP-T on builds that use it (which is a bad idea anyway for root of trust concerns)