Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz""

Revert "x86: do not use cpufreq_quick_get() for /proc/cpuinfo "cpu MHz""

BugLink: http://bugs.launchpad.net/bugs/1731971
commit 890da9cf098364b11a7f7f5c22fa652531624d03 upstream.

This reverts commit 51204e0639c49ada02fd823782ad673b6326d748.

There wasn't really any good reason for it, and people are complaining
(rightly) that it broke existing practice.

Cc: Len Brown <len.brown@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>