Use schedutil governor by default

This is such a common default that there's no reason for Nerves not to
use it as well.

The article at https://lwn.net/Articles/682391/ describes the issues and
why schedutil is a good option unless there are overarching concerns
with a particular project.

Author: ConnorRigby

linux/linux-5.10.defconfig

@@ -39,10 +39,10 @@ CONFIG_ARM_PSCI=y
 # CONFIG_ATAGS is not set
 CONFIG_CPU_FREQ=y
 CONFIG_CPU_FREQ_STAT=y
-CONFIG_CPU_FREQ_DEFAULT_GOV_CONSERVATIVE=y
 CONFIG_CPU_FREQ_GOV_POWERSAVE=y
 CONFIG_CPU_FREQ_GOV_USERSPACE=y
 CONFIG_CPU_FREQ_GOV_ONDEMAND=y
+CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
 CONFIG_CPUFREQ_DT=y
 # CONFIG_ARM_OMAP2PLUS_CPUFREQ is not set
 CONFIG_CPU_IDLE=y