kernelci reports a failure of the ip28_defconfig build after upgrading its
gcc version:
arch/mips/sgi-ip22/Platform:29: *** gcc doesn't support needed option -mr10k-cache-barrier=store. Stop.
The problem apparently is that the -mr10k-cache-barrier=store option is now
rejected for CPUs other than r10k. Explicitly including the CPU in the
check fixes this and is safe because both options were introduced in
gcc-4.4.