drm/amdgpu/display: reduce stack size in dml32_ModeSupportAndSystemConfigurationFull()

drm/amdgpu/display: reduce stack size in dml32_ModeSupportAndSystemConfigurationFull()

Move more stack variable in to dummy vars structure on the heap.

Fixes stack frame size errors:
drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c: In function 'dml32_ModeSupportAndSystemConfigurationFull':
drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn32/display_mode_vba_32.c:3833:1: error: the frame size of 2720 bytes is larger than 2048 bytes [-Werror=frame-larger-than=]
 3833 | } // ModeSupportAndSystemConfigurationFull
      | ^

Fixes: 970399712a32 ("drm/amd/display: DML changes for DCN32/321")
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Rodrigo Siqueira Jordao <Rodrigo.Siqueira@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>