drm/amd: Decrease message level for legacy-pm, kv-dpm and si-dpm

drm/amd: Decrease message level for legacy-pm, kv-dpm and si-dpm

legacy-pm, kv-dpm and si-dpm have prints while changing power states
that don't have a level and thus are printed by default. These are
not useful at runtime for most people, so decrease them to debug.

Reported-by: Alexandre Demers <alexandre.f.demers@gmail.com>
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4322
Reviewed-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://lore.kernel.org/r/20250627143432.3222843-1-superm1@kernel.org
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>