Documentation: cpufreq: intel_pstate: fix typo

This just swaps a colon for a quote in the intel_pstate documentation.

Signed-off-by: Felipe Franciosi <[e-mail]>
Signed-off-by: Rafael J. Wysocki <[e-mail]>

Documentation/cpu-freq/intel-pstate.txt

···
 The driver provides minimum and maximum frequency limits and callbacks to set a
 policy. The policy in cpufreq sysfs is referred to as the "scaling governor".
 The cpufreq core can request the driver to operate in any of the two policies:
-"performance: and "powersave". The driver decides which frequency to use based
+"performance" and "powersave". The driver decides which frequency to use based
 on the above policy selection considering minimum and maximum frequency limits.
 
 The Intel P-State driver falls under the latter category, which implements the