Fix Unlit being unable to use materials in range [512; 4096)

Only PBS uses the first 9 bits, as the rest is used for skeletal
animations.
Unlit can use the full index.

Regression started in v2.3

Thanks user haloman30 for discovering this bug:
https://forums.ogre3d.org/viewtopic.php?p=556165#p556165

Samples/Media/Hlms/Unlit/Any/800.PixelShader_piece_ps.any

@@ -43,7 +43,7 @@
 @piece( LoadMaterial )
 	@property( !lower_gpu_overhead )
 		@property( syntax != metal )
-			ushort materialId	= worldMaterialIdx[inPs.drawId].x & 0x1FFu;
+			ushort materialId	= worldMaterialIdx[inPs.drawId].x;
 			#define material materialArray[materialId]
 		@else
 			#define material materialArray[inPs.materialId]