octeontx2: cn20k: Coordinate default rules with NIX LF lifecycle

octeontx2: cn20k: Coordinate default rules with NIX LF lifecycle

Add NIX_LF_DONT_FREE_DFT_IDXS so the PF can send NIX LF free during hw
reinit or teardown without the AF freeing CN20K default NPC rule indexes
while the driver still owns that state (otx2_init_hw_resources and
otx2_free_hw_resources).

On CN20K, allocate default NPC rules from NIX LF alloc before
nix_interface_init, roll back with npc_cn20k_dft_rules_free on failure,
and free from NIX LF free when the new flag is not set. Tighten
rvu_mbox_handler_nix_lf_alloc error handling: use a single rc, propagate
qmem_alloc and other errors, and set -ENOMEM only when kcalloc fails
(remove the blanket -ENOMEM at the free_mem path).

Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
Link: https://patch.msgid.link/20260609040453.711932-7-rkannoth@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>