net: ncsi: Fix GCPS 64-bit member variables

net: ncsi: Fix GCPS 64-bit member variables

Correct Get Controller Packet Statistics (GCPS) 64-bit wide member
variables, as per DSP0222 v1.0.0 and forward specs. The Driver currently
collects these stats, but they are yet to be exposed to the user.
Therefore, no user impact.

Statistics fixes:
Total Bytes Received (byte range 28..35)
Total Bytes Transmitted (byte range 36..43)
Total Unicast Packets Received (byte range 44..51)
Total Multicast Packets Received (byte range 52..59)
Total Broadcast Packets Received (byte range 60..67)
Total Unicast Packets Transmitted (byte range 68..75)
Total Multicast Packets Transmitted (byte range 76..83)
Total Broadcast Packets Transmitted (byte range 84..91)
Valid Bytes Received (byte range 204..11)

Signed-off-by: Hari Kalavakunta <kalavakunta.hari.prasad@gmail.com>
Reviewed-by: Paul Fertser <fercerpav@gmail.com>
Link: https://patch.msgid.link/20250410012309.1343-1-kalavakunta.hari.prasad@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>