drm/amd/display: Address 'srf_updates' not described in 'could_mpcc_tree_change_for_active_pipes'

Fixes the following:

drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc.c:3928: warning: Function parameter or member 'srf_updates' not described in 'could_mpcc_tree_change_for_active_pipes'

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>