drm/bridge: analogix_dp: Don't use ANALOGIX_DP_PLL_CTL to control pll

There is no register named ANALOGIX_DP_PLL_CTL in Rockchip edp phy reg
list.  We should use BIT_4 in ANALOGIX_DP_PD to control the pll power
instead of ANALOGIX_DP_PLL_CTL.

Cc: Douglas Anderson <dianders@chromium.org>
Signed-off-by: zain wang <wzz@rock-chips.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180423105003.9004-15-enric.balletbo@collabora.com

drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c

@@ -230,16 +230,20 @@ enum pll_status analogix_dp_get_pll_lock_status(struct analogix_dp_device *dp)
 void analogix_dp_set_pll_power_down(struct analogix_dp_device *dp, bool enable)
 {
 	u32 reg;
+	u32 mask = DP_PLL_PD;
+	u32 pd_addr = ANALOGIX_DP_PLL_CTL;
 
-	if (enable) {
-		reg = readl(dp->reg_base + ANALOGIX_DP_PLL_CTL);
-		reg |= DP_PLL_PD;
-		writel(reg, dp->reg_base + ANALOGIX_DP_PLL_CTL);
-	} else {
-		reg = readl(dp->reg_base + ANALOGIX_DP_PLL_CTL);
-		reg &= ~DP_PLL_PD;
-		writel(reg, dp->reg_base + ANALOGIX_DP_PLL_CTL);
+	if (dp->plat_data && is_rockchip(dp->plat_data->dev_type)) {
+		pd_addr = ANALOGIX_DP_PD;
+		mask = RK_PLL_PD;
 	}
+
+	reg = readl(dp->reg_base + pd_addr);
+	if (enable)
+		reg |= mask;
+	else
+		reg &= ~mask;
+	writel(reg, dp->reg_base + pd_addr);
 }
 
 void analogix_dp_set_analog_power_down(struct analogix_dp_device *dp,