After revivesa merge kernel builts fail on/for cobalt/mipsel

[Markus W Kilbinger <mk%kilbi.de@localhost>]

... with

qie# /usr/u/NetBSD/tools-cobalt/bin/nbmake-cobalt
making sure the compat library is up to date...
`libcompat.a' is up to date.
making sure the kern library is up to date...
`libkern.o' is up to date.
    compile  COCHISE/mips_machdep.o
../../../../arch/mips/mips/mips_machdep.c: In function 'cpu_upcall':
../../../../arch/mips/mips/mips_machdep.c:1716: error: 'struct proc' has no 
member named 'p_smutex'

*** Failed target:  mips_machdep.o