page_pool: fix &page_pool_params kdoc issues

After the tagged commit, @netdev got documented twice and the kdoc
script didn't notice that. Remove the second description added later
and move the initial one according to the field position.

After merging commit 5f8e4007c1 ("kernel-doc: fix
struct_group_tagged() parsing"), kdoc requires to describe struct
groups as well. &page_pool_params has 2 struct groups which
generated new warnings, describe them to resolve this.

Fixes: 403f11ac9a ("page_pool: don't use driver-set flags field directly")
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/r/20240524112859.2757403-1-aleksander.lobakin@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/page_pool/types.h

@@ -45,16 +45,17 @@ struct pp_alloc_cache {
 
 /**
  * struct page_pool_params - page pool parameters
+ * @fast:	params accessed frequently on hotpath
  * @order:	2^order pages on allocation
  * @pool_size:	size of the ptr_ring
  * @nid:	NUMA node id to allocate from pages from
  * @dev:	device, for DMA pre-mapping purposes
- * @netdev:	netdev this pool will serve (leave as NULL if none or multiple)
  * @napi:	NAPI which is the sole consumer of pages, otherwise NULL
  * @dma_dir:	DMA mapping direction
  * @max_len:	max DMA sync memory size for PP_FLAG_DMA_SYNC_DEV
  * @offset:	DMA sync address offset for PP_FLAG_DMA_SYNC_DEV
- * @netdev:	corresponding &net_device for Netlink introspection
+ * @slow:	params with slowpath access only (initialization and Netlink)
+ * @netdev:	netdev this pool will serve (leave as NULL if none or multiple)
  * @flags:	PP_FLAG_DMA_MAP, PP_FLAG_DMA_SYNC_DEV, PP_FLAG_SYSTEM_POOL
  */
 struct page_pool_params {