GSdx-d3d11: Add support for depth convert format in texture sampler.

Idea is to allot partial support of depth fmt on the new depth convert
format, this way we can utilize channel shuffle on Red, Blue or gXbY
channels with depth shader conversion.

Terminator 3 hits this code path and seems to fix a transparent wall.
Other games will probably benefit from this as well.

plugins/GSdx/Renderers/DXCommon/GSRendererDX.cpp

@@ -240,6 +240,17 @@ void GSRendererDX::EmulateTextureSampler(const GSTextureCache::Source* tex)
 			bilinear &= m_vt.IsLinear();
 		}
 
+		// Depth format
+		if (tex->m_texture->GetType() == GSTexture::DepthStencil)
+		{
+			// Require a float conversion if the texure is a depth format
+			m_ps_sel.depth_fmt = (psm.bpp == 16) ? 2 : 1;
+			// m_vs_sel.int_fst = !PRIM->FST; // select float/int coordinate
+
+			// Don't force interpolation on depth format
+			bilinear &= m_vt.IsLinear();
+		}
+
 		GSVector4 half_offset = RealignTargetTextureCoordinate(tex);
 		vs_cb.Texture_Scale_Offset.z = half_offset.x;
 		vs_cb.Texture_Scale_Offset.w = half_offset.y;