net: cadence: macb: Convert to get_stats64

Convert the existing get_stats implementation to get_stats64. Since we
now report 64-bit values, increase the counters to 64-bits as well.

Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Link: https://patch.msgid.link/20250214212703.2618652-2-sean.anderson@linux.dev


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