GSdx: fix a crash on Intel GM 910/915 and other PS 2.0-only cards, by removing a reference to VPOS (which is PS3.0 only).

git-svn-id: http://pcsx2.googlecode.com/svn/trunk@2651 96395faa-99c1-11dd-bbfe-3dabce05a288

plugins/GSdx/res/convert.fx

@@ -47,7 +47,11 @@ struct VS_OUTPUT
 
 struct PS_INPUT
 {
+#if SHADER_MODEL < 0x300
+	float4 p : TEXCOORD1;
+#else
 	float4 p : VPOS;
+#endif
 	float2 t : TEXCOORD0;
 };