Revert "asahi: don't canonicalize nans/flush denorms when copying"

This reverts commit ab7fb3d400.

This breaks ./arb_copy_image-formats -auto --samples=4 since we need the blit
path for compression transitions. The correct thing to do is cast the formats.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27616>

src/gallium/drivers/asahi/agx_blit.c

@@ -412,10 +412,6 @@ try_copy_via_blit(struct pipe_context *pctx, struct pipe_resource *dst,
    if (dst->target != src->target)
       return false;
 
-   /* TODO: float formats don't roundtrip, cast */
-   if (util_format_is_float(dst->format) || util_format_is_float(src->format))
-      return false;
-
    struct pipe_blit_info info = {
       .dst =
          {