cpufreq/amd-pstate: Store the boost numerator as highest perf again

commit ad4caad5 ("cpufreq: amd-pstate: Merge
amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
changed the semantics for highest perf and commit 18d9b522
("cpufreq/amd-pstate: Use nominal perf for limits when boost is disabled")
worked around those semantic changes.

This however is a confusing result and furthermore makes it awkward to
change frequency limits and boost due to the scaling differences. Restore
the boost numerator to highest perf again.

Suggested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Fixes: ad4caad5 ("cpufreq: amd-pstate: Merge amd_pstate_highest_perf_set() into amd_get_boost_ratio_numerator()")
Link: https://lore.kernel.org/r/20241209185248.16301-2-mario.limonciello@amd.com


Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>