drm: exynos: hdmi: fix interrupt handling

This patch fixes 'unsigned < 0' check in probe. Moreover it
releases an interrupt at remove.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index b3a802b..3902917 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -64,8 +64,8 @@
 	struct mutex			hdmi_mutex;
 
 	void __iomem			*regs;
-	unsigned int			external_irq;
-	unsigned int			internal_irq;
+	int				external_irq;
+	int				internal_irq;
 
 	struct i2c_client		*ddc_port;
 	struct i2c_client		*hdmiphy_port;
@@ -2424,6 +2424,7 @@
 	pm_runtime_disable(dev);
 
 	free_irq(hdata->internal_irq, hdata);
+	free_irq(hdata->external_irq, hdata);
 
 	hdmi_resources_cleanup(hdata);