Also rid some unused ones.

This patch solves 2000 warnings!

Fixes the following W=1 kernel build warning(s):

 In file included from drivers/gpu/drm/amd/amdgpu/../display/dc/dc_types.h:33,
 from drivers/gpu/drm/amd/amdgpu/../display/dc/dm_services_types.h:30,
 from drivers/gpu/drm/amd/amdgpu/../display/dc/dm_services.h:35,
 from drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_helpers.c:35:
 At top level:
 drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:76:32: warning: ‘dc_fixpt_ln2_div_2’ defined but not used [-Wunused-const-variable=]
 76 | static const struct fixed31_32 dc_fixpt_ln2_div_2 = { 1488522236LL };
 | ^~~~~~~~~~~~~~~~~~
 drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:75:32: warning: ‘dc_fixpt_ln2’ defined but not used [-Wunused-const-variable=]
 75 | static const struct fixed31_32 dc_fixpt_ln2 = { 2977044471LL };
 | ^~~~~~~~~~~~
 drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:74:32: warning: ‘dc_fixpt_e’ defined but not used [-Wunused-const-variable=]
 74 | static const struct fixed31_32 dc_fixpt_e = { 11674931555LL };
 | ^~~~~~~~~~
 drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:73:32: warning: ‘dc_fixpt_two_pi’ defined but not used [-Wunused-const-variable=]
 73 | static const struct fixed31_32 dc_fixpt_two_pi = { 26986075409LL };
 | ^~~~~~~~~~~~~~~
 drivers/gpu/drm/amd/amdgpu/../display/include/fixed31_32.h:72:32: warning: ‘dc_fixpt_pi’ defined but not used [-Wunused-const-variable=]
 72 | static const struct fixed31_32 dc_fixpt_pi = { 13493037705LL };
 | ^~~~~~~~~~~

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>