cpufreq/amd-pstate: Remove the redundant des_perf clamping in adjust_perf

cpufreq/amd-pstate: Remove the redundant des_perf clamping in adjust_perf

des_perf is later on clamped between min_perf and max_perf in
amd_pstate_update. So, remove the redundant clamping from
amd_pstate_adjust_perf.

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/20250205112523.201101-5-dhananjay.ugwekar@amd.com
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>