net: mvneta: enable jumbo frames if the loaded XDP program support frags

Enable the capability to receive jumbo frames even if the interface is
running in XDP mode if the loaded program declare to properly support
xdp frags. At same time reject a xdp program not supporting xdp frags
if the driver is running in xdp frags mode.

Acked-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/6909f81a3cbb8fb6b88e914752c26395771b882a.1642758637.git.lorenzo@kernel.org


Signed-off-by: Alexei Starovoitov <ast@kernel.org>