This doesn't have any benefit apart from saving a small amount of memory
when it is disabled. The ifdef hackery in the code makes it dirty
unnecessarily.

Clean it up by removing the Kconfig option completely. Few defconfigs
are also updated and CONFIG_CPU_FREQ_STAT_DETAILS is replaced with
CONFIG_CPU_FREQ_STAT now in them, as users wanted stats to be enabled.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>