net: loopback: set default mtu to 64K

loopback current mtu of 16436 bytes allows no more than 3 MSS TCP
segments per frame, or 48 Kbytes. Changing mtu to 64K allows TCP
stack to build large frames and significantly reduces stack overhead.

Performance boost on bulk TCP transferts can be up to 30 %, partly
because we now have one ACK message for two 64KB segments, and a lower
probability of hitting /proc/sys/net/ipv4/tcp_reordering default limit.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: flar2 <asegaert@gmail.com>
arm/dt: msm8974: Increase "ib" values for VIDC DDR bandwidth request

As per the recommendation by performance team, update the
"ib" values for DDR BW requests. This change fixes the
display under-runs seen during video playback.

Change-Id: I137814c82b257b8c751dab9df4f705e43fd5643e
Signed-off-by: Vinay Kalia <vkalia@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>