radv: fix radv_layout_dcc_compressed() when image doesn't have DCC

radv: fix radv_layout_dcc_compressed() when image doesn't have DCC

num_dcc_levels means that DCC is supported, but this doesn't
mean that it's enabled by the driver. Instead, we should rely
on radv_image_has_dcc().

This fixes some multisample regressions since 0babc8e5d66
("radv: fix picking the method for resolve subpass") on Vega.
This is because the resolve method changed from HW to FS, but
those fails are totally unexpected, so there might some
differences between Polaris and Vega here.

Fixes: 44fcf587445 ("radv: Disable DCC for GENERAL layout and compute transfer dest.")
Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>