drm/amdgpu: Assign boolean values to a bool variable

Fix the following coccicheck warnings:

./drivers/gpu/drm/amd/display/dc/dml/dcn30/display_rq_dlg_calc_30.c:
1009:6-16: WARNING: Assignment of 0/1 to bool variable.

./drivers/gpu/drm/amd/display/dc/dml/dcn30/display_rq_dlg_calc_30.c:
200:2-10: WARNING: Assignment of 0/1 to bool variable.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>