Unable to make buildkernel (fresh cvsup to RELENG_6)

[Laurence Sanford]

I'm upgrading a 5.4 machine to 6. I can buildworld successfully, but 
attempting to make buildkernel fails:

HEADERS -I. -I@ -I@/contrib/altq -I@/../include -I/usr/include 
-I/usr/obj/usr/src/sys/Colossus /usr/src/sys/modules/ti/../../pci/if_ti.c
/usr/src/sys/modules/ti/../../pci/if_ti.c:2536:35: macro 
"VLAN_INPUT_TAG" requires 4 arguments, but only 3 given
mkdep: compile failed
*** Error code 1

Stop in /usr/src/sys/modules/ti.
*** Error code 1

Stop in /usr/src/sys/modules.
*** Error code 1

Stop in /usr/obj/usr/src/sys/Colossus.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.

Yes, it's a customer kernel, however, it's worth noting that GENERIC has 
failed in exactly the same place with the same error. Any suggestions?