Set new DPI for Shamu QHD panel

Change-Id: I8bc8f64bb3aacb5fe458732798d2554247264465
diff --git a/device.mk b/device.mk
index 7c5f5fb..9d27562 100644
--- a/device.mk
+++ b/device.mk
@@ -190,7 +190,7 @@
     ro.opengles.version=196608
 
 PRODUCT_PROPERTY_OVERRIDES += \
-    ro.sf.lcd_density=480
+    ro.sf.lcd_density=640
 
 PRODUCT_PROPERTY_OVERRIDES += \
     persist.hwc.mdpcomp.enable=true