accel/habanalabs: separate nonce from max_size in cpucp_packet struct

accel/habanalabs: separate nonce from max_size in cpucp_packet struct

In struct cpucp_packet both nonce and data_max_size members are in an
union overlapping each other. This is a problem as they both are used
in attestation and info_signed packets.
The solution here is to move the nonce member to a different union under
the same structure.

Signed-off-by: Dani Liberman <dliberman@habana.ai>
Reviewed-by: Ofir Bitton <obitton@habana.ai>
Signed-off-by: Ofir Bitton <obitton@habana.ai>