radeonsi/gfx10: disable DCC image stores

Uncompressed image stores are usually faster.

Also, the driver didn't set WRITE_COMPRESS_ENABLE, so I don't know
what the hw did for image stores.

src/gallium/drivers/radeonsi/si_descriptors.c

@@ -739,7 +739,7 @@ static void si_set_shader_image_desc(struct si_context *ctx,
 		assert(fmask_desc || tex->surface.fmask_size == 0);
 
 		if (uses_dcc && !skip_decompress &&
-		    ((ctx->chip_class <= GFX9 && view->access & PIPE_IMAGE_ACCESS_WRITE) ||
+		    (view->access & PIPE_IMAGE_ACCESS_WRITE ||
 		     !vi_dcc_formats_compatible(screen, res->b.b.format, view->format))) {
 			/* If DCC can't be disabled, at least decompress it.
 			 * The decompression is relatively cheap if the surface

src/gallium/drivers/radeonsi/si_shader_tgsi_mem.c

@@ -196,8 +196,7 @@ LLVMValueRef si_load_image_desc(struct si_shader_context *ctx,
 	else
 		rsrc = ac_build_load_to_sgpr(&ctx->ac, list, index);
 
-	if (ctx->ac.chip_class <= GFX9 &&
-	    desc_type == AC_DESC_IMAGE && uses_store)
+	if (desc_type == AC_DESC_IMAGE && uses_store)
 		rsrc = force_dcc_off(ctx, rsrc);
 	return rsrc;
 }