cpufreq: Documentation: Update description of rate_limit_us default value

Due to commit 37c6dcc ("cpufreq: Remove LATENCY_MULTIPLIER")
updating the acquisition logic of cpufreq_policy_transition_delay_us(),
the original description of 2 ms has become inaccurate.

Therefore, update the description of the default value for
rate_limit_us from 2ms to 1ms.

Signed-off-by: Yaxiong Tian <tianyaxiong@kylinos.cn>
[ rjw: Subject and changelog edits ]
Link: https://patch.msgid.link/20260203093501.1138721-1-tianyaxiong@kylinos.cn
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Yaxiong Tian

Documentation/admin-guide/pm/cpufreq.rst

@@ -439,7 +439,7 @@ This governor exposes only one tunable:
 ``rate_limit_us``
 	Minimum time (in microseconds) that has to pass between two consecutive
 	runs of governor computations (default: 1.5 times the scaling driver's
-	transition latency or the maximum 2ms).
+	transition latency or 1ms if the driver does not provide a latency value).
 
 	The purpose of this tunable is to reduce the scheduler context overhead
 	of the governor which might be excessive without it.