Change in coreboot[master]: intel/common/../systemagent: Add sa_get_mchbar_base api

[Subrata Banik (Code Review)]

Attention is currently required from: Wonkyu Kim, Paul Menzel, Angel Pons.
Subrata Banik has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/63615 )

Change subject: intel/common/../systemagent: Add sa_get_mchbar_base api
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Patch Set 8:

(2 comments)

File src/soc/intel/common/block/systemagent/systemagent_early.c:

https://review.coreboot.org/c/coreboot/+/63615/comment/4cc4b1fb_dbefee6f 
PS8, Line 89: if (mchbar_lo & 0x1)
what if mchbar_lo and hi value is zero and BAR enable bit is set? we would run into the problem isn't it ?

https://review.coreboot.org/c/coreboot/+/63615/comment/f499c055_cd823d30 
PS8, Line 92:         
tab ?