cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled

cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled

When boost has been disabled the limit for perf should be nominal perf not
the highest perf.  Using the latter to do calculations will lead to
incorrect values that are still above nominal.

Fixes: ad4caad58d91 ("cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
Reported-by: Peter Jung <ptr1337@cachyos.org>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219348
Reviewed-by: Perry Yuan <perry.yuan@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Tested-by: Dhananjay Ugwekar <dhananjay.ugwekar@amd.com>
Link: https://lore.kernel.org/r/20241012174519.897-1-mario.limonciello@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>