Change in coreboot[master]: mb/intel/shadowmountain: Add flash layout for shadowmountain

[Paul Menzel (Code Review)]

Attention is currently required from: V Sowmya, Sugnan Prabhu S, Tim Wawrzynczak, Balaji Manigandan, Aamir Bohra.
Paul Menzel has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/49478 )

Change subject: mb/intel/shadowmountain: Add flash layout for shadowmountain
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Patch Set 3:

(2 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/49478/comment/2bdfa4c4_179dcb23 
PS3, Line 7:  for shadowmountain
Already part of the prefix.

https://review.coreboot.org/c/coreboot/+/49478/comment/5db9ca4f_a0a8d5c4 
PS3, Line 9: This patch adds the flash layout for shadowmountain.
You could mention the parts, and if you copied it from somewhere.