OMAPDSS: HDMI: hot plug detect fix

The "OMAPDSS: HDMI: PHY burnout fix" commit switched the HDMI driver
over to using a GPIO for plug detect.  Unfortunately the ->detect()
method was not also updated, causing HDMI to no longer work for the
omapdrm driver (because it would actually check if a connection was
detected before attempting to enable display).
Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/dss/ti_hdmi_4xxx_ip.c

@@ -479,14 +479,7 @@ int ti_hdmi_4xxx_read_edid(struct hdmi_ip_data *ip_data,
 
 bool ti_hdmi_4xxx_detect(struct hdmi_ip_data *ip_data)
 {
-	int r;
-
-	void __iomem *base = hdmi_core_sys_base(ip_data);
-
-	/* HPD */
-	r = REG_GET(base, HDMI_CORE_SYS_SYS_STAT, 1, 1);
-
-	return r == 1;
+	return gpio_get_value(ip_data->hpd_gpio);
 }
 
 static void hdmi_core_init(struct hdmi_core_video_config *video_cfg,