octeontx2-af: npc: cn20k: Add new mailboxes for CN20K silicon

octeontx2-af: npc: cn20k: Add new mailboxes for CN20K silicon

To enable enhanced MCAM capabilities for CN20K, the struct mcam_entry
has been extended to support expanded keyword requirements.
Specifically, the kw and kw_mask arrays have been increased from
a size of 7 to 8 to accommodate the additional keyword field
introduced for CN20K.

To ensure seamless integration while preserving compatibility
with existing platforms, dedicated CN20K-specific mailboxes
have been introduced that leverage the updated struct mcam_entry.
This approach allows CN20K to utilize the extended structure
without impacting current implementations.

This patch identifies the relevant mailboxes and introduces the
following CN20K-specific additions:

New mailboxes added:
1. `NPC_CN20K_MCAM_WRITE_ENTRY`
2. `NPC_CN20K_MCAM_ALLOC_AND_WRITE_ENTRY`
3. `NPC_CN20K_MCAM_READ_ENTRY`
4. `NPC_CN20K_MCAM_READ_BASE_RULE`

Signed-off-by: Suman Ghosh <sumang@marvell.com>
Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
Link: https://patch.msgid.link/20260224080009.4147301-9-rkannoth@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>