Documentation: cpufreq: delete duplicate description of sysfs interface 'scaling_driver'

The file 'Documentation/cpu-freq/user-guide.txt' has duplicate
description of sysfs interface 'scaling_driver'.

[first]
scaling_driver : this file shows what cpufreq driver is
used to set the frequency on this CPU

[second]
scaling_driver : Hardware driver for cpufreq.

Although this does not affect anything, I think we should only have
one. so delete the second one because the first one is described in
more detail.

Signed-off-by: Wang Long <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

Documentation/cpu-freq/user-guide.txt

···
 related_cpus :			List of Online + Offline CPUs that need software
 				coordination of frequency.
 
-scaling_driver :		Hardware driver for cpufreq.
-
 scaling_cur_freq :		Current frequency of the CPU as determined by
 				the governor and cpufreq core, in KHz. This is
 				the frequency the kernel thinks the CPU runs