msm: rndis_ipa: flow control outstanding watermark increase

This change increases the watermark for the netdev
outstanding packet.
It is needed to allow high throughput on LAN data path.

Change-Id: I65caea79fdeeea7af2393a0ec46f483571d2fa93
Signed-off-by: Talel Shenhar <tatias@codeaurora.org>