net: airoha: Add missing field to ppe_mbox_data struct

The official Airoha EN7581 firmware requires adding max_packet field in
ppe_mbox_data struct while the unofficial one used to develop the Airoha
EN7581 flowtable support does not require this field.
This patch does not introduce any real backwards compatible issue since
EN7581 fw is not publicly available in linux-firmware or other
repositories (e.g. OpenWrt) yet and the official fw version will use this
new layout. For this reason this change needs to be backported.
Moreover, make explicit the padding added by the compiler introducing
the rsv array in init_info struct.
At the same time use u32 instead of int for init_info and set_info
struct definitions in ppe_mbox_data struct.

Fixes: 23290c7b ("net: airoha: Introduce Airoha NPU support")
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20250506-airoha-en7581-fix-ppe_mbox_data-v5-1-29cabed6864d@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>