disp: msm: sde: program master intf register for single intf

This change adds the programming of the master interface
register for single interface configurations.
Setting this register is required by hw-fencing feature
to distinguish primary interfaces vs wb.

Change-Id: I84936ebd6a9f2d67cf98c19a51ce3a132c648a2d
Signed-off-by: Ingrid Gallardo <quic_ingridg@quicinc.com>
Signed-off-by: Christina Oliveira <quic_coliveir@quicinc.com>

msm/sde/sde_hw_ctl.c

@@ -1003,6 +1003,8 @@ static int sde_hw_ctl_intf_cfg_v1(struct sde_hw_ctl *ctx,
 
 	if (cfg->intf_count > 1)
 		intf_master = BIT(cfg->intf_master - INTF_0);
+	else if (cfg->intf_count == 1)
+		intf_master = BIT(cfg->intf[0] - INTF_0);
 
 	for (i = 0; i < cfg->wb_count; i++) {
 		if (cfg->wb[i])