platform/mellanox: mlxbf-tmfifo: Drop jumbo frames

This commit drops over-sized network packets to avoid tmfifo
queue stuck.

Fixes: 1357dfd7 ("platform/mellanox: Add TmFifo driver for Mellanox BlueField Soc")
Signed-off-by: Liming Sun <limings@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Reviewed-by: David Thompson <davthompson@nvidia.com>
Link: https://lore.kernel.org/r/9318936c2447f76db475c985ca6d91f057efcd41.1693322547.git.limings@nvidia.com


Signed-off-by: Hans de Goede <hdegoede@redhat.com>