cpufreq: Remove max_freq_req update for pre-existing policy

policy->max_freq_req QoS constraint represents the maximal allowed
frequency than can be requested. It is set by:
 - writing to policyX/scaling_max sysfs file
 - toggling the cpufreq/boost sysfs file

Upon calling freq_qos_update_request(), a successful update
of the max_freq_req value triggers cpufreq_notifier_max(),
followed by cpufreq_set_policy() which update the requested
frequency for the policy.
If the new max_freq_req value is not different from the
original value, no frequency update is triggered.

In a specific sequence of toggling:
 - cpufreq/boost sysfs file
 - CPU hot-plugging
a CPU could end up with boost enabled but running at the
maximal non-boost frequency, cpufreq_notifier_max() not being
triggered. The following fixed that:
commit 1608f02 ("cpufreq: Fix re-boost issue after hotplugging
a CPU")

The following:
commit dd016f3 ("cpufreq: Introduce a more generic way to
set default per-policy boost flag")
also fixed the issue by correctly setting the max_freq_req
constraint of a policy that is re-activated. This makes the
first fix unnecessary.

As the original issue is fixed by another method,
this patch reverts:
commit 1608f02 ("cpufreq: Fix re-boost issue after hotplugging
a CPU")

Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://patch.msgid.link/20260326204404.1401849-2-pierre.gondois@arm.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: pierregondois

drivers/cpufreq/cpufreq.c

@@ -1484,10 +1484,6 @@ static int cpufreq_policy_online(struct cpufreq_policy *policy,
 
 		blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
 				CPUFREQ_CREATE_POLICY, policy);
-	} else {
-		ret = freq_qos_update_request(policy->max_freq_req, policy->max);
-		if (ret < 0)
-			goto out_destroy_policy;
 	}
 
 	if (cpufreq_driver->get && has_target()) {