Change in coreboot[master]: grunt/treeya: add Realtek ALC5682 codec support

[Martin Roth (Code Review)]

Attention is currently required from: Daniel Kurtz, Kevin Chang, Paul Menzel.
Martin Roth has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/56100 )

Change subject: grunt/treeya: add Realtek ALC5682 codec support
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Patch Set 4:

(1 comment)

File src/mainboard/google/kahlee/variants/treeya/audio.c:

https://review.coreboot.org/c/coreboot/+/56100/comment/8663c643_6bc06899 
PS4, Line 21: if (mmio_dev == NULL)
            : 			break;
> Martin, is "== NULL" a common thing in coreboot? […]

(!mmio_dev) is probably the preferred form, but there are over 1000 places in the code where '== NULL' is used so it's not a big issue.