Change in coreboot[master]: soc/intel/mtl: Do initial SoC commit till bootblock

[Ravishankar Sarawadi (Code Review)]

Attention is currently required from: Felix Singer, Jamie Ryu, Subrata Banik, Ethan Tsao, Ravishankar Sarawadi, Paul Menzel, Raj Astekar.
Ravishankar Sarawadi has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/62772 )

Change subject: soc/intel/mtl: Do initial SoC commit till bootblock
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Patch Set 4:

(3 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/62772/comment/12602d2b_85e284c6 
PS4, Line 9: List of changes:
> Introduce the new device, and write *Meteor Lake* at least once?

Ack

https://review.coreboot.org/c/coreboot/+/62772/comment/10ae9583_f3685979 
PS4, Line 16:
> Is the code all written from scratch?

Meteor Lake SoC code including this bootblock stage code is based of Alder Lake.

Patchset:

PS4:
> @Ravi, we have took AI (action item) from ADL upstream work that going forward, we will upstream bot […]

@subrata, are you suggesting SoC and MB bootblock ONLY code should compile and boot till last post code in bootblock? 
Does the current Make build supports only bootblock code compilation w/o other stages like romstage, ramstage ?