net: ethernet: ti: netcp: Use u64_stats_t with u64_stats_sync properly

net: ethernet: ti: netcp: Use u64_stats_t with u64_stats_sync properly

On 64bit arches, struct u64_stats_sync is empty and provides no help
against load/store tearing. Convert to u64_stats_t to ensure atomic
operations.

Note that does not mean the code is now tear-free: there're u32 counters
unprotected by u64_stats or anything else.

Signed-off-by: David Yang <mmyangfl@gmail.com>
Link: https://patch.msgid.link/20260123164841.2890054-1-mmyangfl@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>