mlxsw: pci: Optimize data buffer access

Before accessing data buffer, call net_prefetch() to load it into the
cache. This change improves driver performance, CPU can handle about
7.1% more packets per second.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/1fa07c510890866a6f201163ab7e78890ba28b3b.1718709196.git.petrm@nvidia.com


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