cpufreq/amd-pstate: Modify the min_perf calculation in adjust_perf callback

cpufreq/amd-pstate: Modify the min_perf calculation in adjust_perf callback

Instead of setting a fixed floor at lowest_nonlinear_perf, use the
min_limit_perf value, so that it gives the user the freedom to lower the
floor further.

There are two minimum frequency/perf limits that we need to consider in
the adjust_perf callback. One provided by schedutil i.e. the sg_cpu->bw_min
value passed in _min_perf arg, another is the effective value of
min_freq_qos request that is updated in cpudata->min_limit_perf. Modify the
code to use the bigger of these two values.

Signed-off-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/r/20250205112523.201101-4-dhananjay.ugwekar@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>