drm/stm: ltdc: fix duplicated arguments

Fix COMPILE_TEST build issue detected with the
rule: "duplicated argument to & or |"

Signed-off-by: Philippe CORNU <philippe.cornu@st.com>
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1495445421-20846-1-git-send-email-philippe.cornu@st.com

drivers/gpu/drm/stm/ltdc.c

@@ -463,7 +463,7 @@ static void ltdc_crtc_mode_set_nofb(struct drm_crtc *crtc)
 	clk_enable(ldev->pixel_clk);
 
 	/* Configures the HS, VS, DE and PC polarities. */
-	val = HSPOL_AL | HSPOL_AL | DEPOL_AL | PCPOL_IPC;
+	val = HSPOL_AL | VSPOL_AL | DEPOL_AL | PCPOL_IPC;
 
 	if (vm.flags & DISPLAY_FLAGS_HSYNC_HIGH)
 		val |= HSPOL_AH;