drm/amd/display/dc/dce80/Makefile: Ignore -Woverride-init warning

drm/amd/display/dc/dce80/Makefile: Ignore -Woverride-init warning

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

 In file included from drivers/gpu/drm/amd/amdgpu/../display/dc/dce80/dce80_resource.c:29:
 drivers/gpu/drm/amd/amdgpu/../include/asic_reg/dce/dce_8_0_sh_mask.h:9546:58: warning: initialized field overwritten [-Woverride-init]
 drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dce_aux.h:213:16: note: in expansion of macro ‘AUX_SW_DATA__AUX_SW_AUTOINCREMENT_DISABLE__SHIFT’
 drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dce_aux.h:102:2: note: in expansion of macro ‘AUX_SF’
 drivers/gpu/drm/amd/amdgpu/../display/dc/dce80/dce80_resource.c:305:2: note: in expansion of macro ‘DCE10_AUX_MASK_SH_LIST’
 drivers/gpu/drm/amd/amdgpu/../include/asic_reg/dce/dce_8_0_sh_mask.h:9546:58: note: (near initialization for ‘aux_shift.AUX_SW_AUTOINCREMENT_DISABLE’)
 drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dce_aux.h:213:16: note: in expansion of macro ‘AUX_SW_DATA__AUX_SW_AUTOINCREMENT_DISABLE__SHIFT’
 drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dce_aux.h:102:2: note: in expansion of macro ‘AUX_SF’
 drivers/gpu/drm/amd/amdgpu/../display/dc/dce80/dce80_resource.c:305:2: note: in expansion of macro ‘DCE10_AUX_MASK_SH_LIST’
 drivers/gpu/drm/amd/amdgpu/../include/asic_reg/dce/dce_8_0_sh_mask.h:9545:56: warning: initialized field overwritten [-Woverride-init]
 drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dce_aux.h:213:16: note: in expansion of macro ‘AUX_SW_DATA__AUX_SW_AUTOINCREMENT_DISABLE_MASK’
 drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dce_aux.h:102:2: note: in expansion of macro ‘AUX_SF’

NB: Snipped lots for the sake of brevity

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>