drm/amd/pm: fix amdgpu_pm_info power display units

drm/amd/pm: fix amdgpu_pm_info power display units

amdgpu_pm_info displayed power sensor readings with the wrong fractional unit.
It treated the low byte of the raw sensor value as the decimal part of watts,
while that field represents milliwatts in the decoded value. As a result,
debugfs could report misleading SoC power when the remainder was not already
a two-digit centiwatt value.

Example with query = 0x00000354:

  raw field        value
  ---------------------
  query >> 8       3 W
  query & 0xff     84 mW
  decoded power    3084 mW

  output           value
  ---------------------
  before           3.84 W
  after            3.08 W

Fixes: f0b8f65b4825 ("drm/amd/amdgpu: fix the GPU power print error in pm info")
Signed-off-by: Yang Wang <kevinyang.wang@amd.com>
Reviewed-by: Asad Kamal <asad.kamal@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 01992b121fb652c753d37e0c1427a2d1a557d2b1)
Cc: stable@vger.kernel.org