drm/amd/display: use true, false for bool variable in dcn20_hwseq.c

Fixes coccicheck warning:

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c:186:6-14: WARNING: Assignment of 0/1 to bool variable
drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c:189:2-10: WARNING: Assignment of 0/1 to bool variable
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c

@@ -183,10 +183,10 @@ void dcn20_enable_power_gating_plane(
 	struct dce_hwseq *hws,
 	bool enable)
 {
-	bool force_on = 1; /* disable power gating */
+	bool force_on = true; /* disable power gating */
 
 	if (enable)
-		force_on = 0;
+		force_on = false;
 
 	/* DCHUBP0/1/2/3/4/5 */
 	REG_UPDATE(DOMAIN0_PG_CONFIG, DOMAIN0_POWER_FORCEON, force_on);