config: enable default cpufreq governors for sdxnightjar target

Enable the default available cpufreq governor used to scale
cpu frequency based on the load for sdxnightjar perf config.

Change-Id: I93aeb27350562fe1c488c22d5ac24b80b4a9fdf4
Signed-off-by: Santosh Mardi <gsantosh@codeaurora.org>