[head tinderbox] failure on sparc64/sparc64

[Joseph Koshy]

> linking kernel
> hwpmc_mod.o(.text+0x6308): In function `load':
> : undefined reference to `pmc_md_finalize'
> *** Error code 1

Uh-oh, I get to wear the pointy hat.

Should be fixed in #185168.

Koshy