drm/amdgpu/swm14: Update power limit logic

Take into account the limits from the vbios.  Ported
from the SMU13 code.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4352


Reviewed-by: Jesse Zhang <Jesse.Zhang@amd.com>
Reviewed-by: Kenneth Feng <kenneth.feng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>