While working on a few patches for schedutil I noticed that the CFS cpufreq hooks depend on PELT, which depends on CONFIG_SMP.
I compiled and ran a UP kernel with intel_pstate. Running a cpu-bound task did not result in the frequency increasing beyond fmin. For some reason ondemand is working for me with the same test, not sure why yet. It appears dbs/intel-pstate/schedutil have a dependency on CONFIG_SMP now. Or am I missing something?