kernel: configs: add freq stat to sysfs

kernel: configs: add freq stat to sysfs

BugLink: http://bugs.launchpad.net/bugs/1763040
It's useful for testing cpu frequency

Signed-off-by: Ramon Fried <rfried@codeaurora.org>
Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
(cherry picked from commit 5c4ed6e4d87964c606cc939c790cddb8760899cd
http://git.linaro.org/landing-teams/working/qualcomm/kernel.git release/qcomlt-4.14)
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>