video: fbdev: omap2: Remove deprecated regulator_can_change_voltage() usage

regulator_can_change_voltage() is deprecated and it's use is not necessary
as commit:
6a0028b3dd67b regulator: Deprecate regulator_can_change_voltage()
describers it clearly.
As there is no practical use of it it can be removed.
At this point the regulator_set_voltage() calls can not be removed as the
DT data need to be fixed first.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/fbdev/omap2/omapfb/dss/dsi.c

@@ -1180,13 +1180,11 @@ static int dsi_regulator_init(struct platform_device *dsidev)
 		return PTR_ERR(vdds_dsi);
 	}
 
-	if (regulator_can_change_voltage(vdds_dsi)) {
-		r = regulator_set_voltage(vdds_dsi, 1800000, 1800000);
-		if (r) {
-			devm_regulator_put(vdds_dsi);
-			DSSERR("can't set the DSI regulator voltage\n");
-			return r;
-		}
+	r = regulator_set_voltage(vdds_dsi, 1800000, 1800000);
+	if (r) {
+		devm_regulator_put(vdds_dsi);
+		DSSERR("can't set the DSI regulator voltage\n");
+		return r;
 	}
 
 	dsi->vdds_dsi_reg = vdds_dsi;

drivers/video/fbdev/omap2/omapfb/dss/hdmi4.c

@@ -114,13 +114,11 @@ static int hdmi_init_regulator(void)
 		return PTR_ERR(reg);
 	}
 
-	if (regulator_can_change_voltage(reg)) {
-		r = regulator_set_voltage(reg, 1800000, 1800000);
-		if (r) {
-			devm_regulator_put(reg);
-			DSSWARN("can't set the regulator voltage\n");
-			return r;
-		}
+	r = regulator_set_voltage(reg, 1800000, 1800000);
+	if (r) {
+		devm_regulator_put(reg);
+		DSSWARN("can't set the regulator voltage\n");
+		return r;
 	}
 
 	hdmi.vdda_reg = reg;

drivers/video/fbdev/omap2/omapfb/dss/hdmi5.c

@@ -131,13 +131,11 @@ static int hdmi_init_regulator(void)
 		return PTR_ERR(reg);
 	}
 
-	if (regulator_can_change_voltage(reg)) {
-		r = regulator_set_voltage(reg, 1800000, 1800000);
-		if (r) {
-			devm_regulator_put(reg);
-			DSSWARN("can't set the regulator voltage\n");
-			return r;
-		}
+	r = regulator_set_voltage(reg, 1800000, 1800000);
+	if (r) {
+		devm_regulator_put(reg);
+		DSSWARN("can't set the regulator voltage\n");
+		return r;
 	}
 
 	hdmi.vdda_reg = reg;