v3dv: remove deferred vkCmdClearAtachments path

v3dv: remove deferred vkCmdClearAtachments path

This was required to handle the case of secondary command buffers that
did not have framebuffer information available from the primary, since
we used to have an implementation that required this information to
be available for the fallback path of vkCmdClearAttachments. Now that
we can handle our our attachment clears in the current subpass by
emitting draw calls, we no longer need the framebuffer information to
be available and we can remove this.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11783>