ipq806x: compile in schedutil governor

Gives users a third option to augment ondemand and performance. Kernel
docs[1] explain differences and this PR empowers users w/ the choice to
select between the older ondemand and newer and more simplistic schedutil
should they wish to use one that is not the performance governor.

1. Documentation/admin-guide/pm/cpufreq.rst

Signed-off-by: John Audia <[email protected]>
[fixed From: to match SoB:]
Signed-off-by: Petr Štetiar <[email protected]>

target/linux/ipq806x/config-5.4

@@ -99,6 +99,7 @@ CONFIG_CPU_FREQ_GOV_COMMON=y
 CONFIG_CPU_FREQ_GOV_ONDEMAND=y
 CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
 # CONFIG_CPU_FREQ_GOV_POWERSAVE is not set
+CONFIG_CPU_FREQ_GOV_SCHEDUTIL=y
 # CONFIG_CPU_FREQ_GOV_USERSPACE is not set
 CONFIG_CPU_FREQ_STAT=y
 CONFIG_CPU_HAS_ASID=y
@@ -503,6 +504,7 @@ CONFIG_UBIFS_FS_ADVANCED_COMPR=y
 CONFIG_UBIFS_FS_LZO=y
 CONFIG_UBIFS_FS_ZLIB=y
 CONFIG_UBIFS_FS_ZSTD=y
+# CONFIG_UCLAMP_TASK is not set
 CONFIG_UEVENT_HELPER_PATH=""
 CONFIG_UNCOMPRESS_INCLUDE="debug/uncompress.h"
 CONFIG_UNWINDER_ARM=y