drm/amd/pm: correct Vega12 swctf limit setting

commit e0ffd340249699ad27a6c91abdfa3e89f7823941 upstream.

Correct the Vega12 thermal swctf limit.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>