[M] Change in coreboot[master]: mb/google/nissa/var/xivu: Fine-tune eMMC DLL

[Shou-Chieh Hsu (Code Review)]

Attention is currently required from: Tarun Tuli, Henry Sun, Paul Menzel, Reka Norman, Nick Vaccaro, Lawrence Chang.

Shou-Chieh Hsu has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/69892 )

Change subject: mb/google/nissa/var/xivu: Fine-tune eMMC DLL
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Patch Set 6:

(1 comment)

Commit Message:

https://review.coreboot.org/c/coreboot/+/69892/comment/71d8c7d3_ac8ba169 
PS2, Line 12: TEST="Use the value to boot on Xivu successfully."
> Before fine-tuning eMMC DLL, execute cold boot 10 cycles, some systems may fail to boot from eMMC. […]

We still need the `TEST=` field, just remove the quote symbol.   
You can add `executing 3000 cycles of cold boot` to TEST as well.