Merge branch 'net-sched-tc-drop-reason'

Victor Nogueira says:

====================
net: sched: Make tc-related drop reason more flexible for remaining qdiscs

This patch builds on Daniel's patch[1] to add initial support of tc drop
reason. The main goal is to distinguish between policy and error drops for
the remainder of the egress qdiscs (other than clsact).
The drop reason is set by cls_api and act_api in the tc skb cb in case
any error occurred in the data path.

Also add new skb drop reasons that are idiosyncratic to TC.

[1] https://lore.kernel.org/all/20231009092655.22025-1-daniel@iogearbox.net

Changes in V5:
- Drop "EXT_" from cookie error's drop reason name in doc

Changes in V4:
- Condense all the cookie drop reasons into one

Changes in V3:
- Removed duplicate assignment
- Rename function tc_skb_cb_drop_reason to tcf_get_drop_reason
- Move zone field upwards in struct tc_skb_cb to move hole to the end of
  the struct

Changes in V2:
- Dropped RFC tag
- Removed check for drop reason being overwritten by filter in cls_api.c
- Simplified logic and removed function tcf_init_drop_reason
====================

Signed-off-by: David S. Miller <davem@davemloft.net>