drm/amd/display: protect remaining FPU-code calls on dcn3.1.x

drm/amd/display: protect remaining FPU-code calls on dcn3.1.x

From [1], I realized two other calls to dcn30 code are associated with
FPU operations and are not protected by DC_FP_* macros:
* dcn30_populate_dml_writeback_from_context()
* dcn30_set_mcif_arb_params()

So, since FPU-associated code is not fully isolated in dcn30, and
dcn3.1.x reuses them, let's wrap their calls properly.

Note: this patch complements the fix from [1].

[1] https://lore.kernel.org/amd-gfx/20220329082957.1662655-1-chandan.vurdigerenataraj@amd.com/

Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>