drm/amd/display: Remove redundant condition in dcn35_calc_blocks_to_gate()

drm/amd/display: Remove redundant condition in dcn35_calc_blocks_to_gate()

pipe_ctx->plane_res.mpcc_inst is of a type that can only hold values
between 0 and 255, so it's always greater than or equal to 0.

Thus the condition 'pipe_ctx->plane_res.mpcc_inst >= 0' was always true
and has been removed.

Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/dc/hwss/dcn35/dcn35_hwseq.c:1023 dcn35_calc_blocks_to_gate() warn: always true condition '(pipe_ctx->plane_res.mpcc_inst >= 0) => (0-255 >= 0)'

Fixes: 6f8b7565cca4 ("drm/amd/display: Add DCN35 HWSEQ")
Cc: Qingqing Zhuo <Qingqing.Zhuo@amd.com>
Cc: Harry Wentland <Harry.Wentland@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Roman Li <roman.li@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Cc: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>