Summary: - This commit updates rndis_smp/defconfig - Adjust stack size to avoid hardfault - Remove CONFIG_NET_TCP_WRITE_BUFFERS temporarily to avoid unstable behaviors with nxplayer + telnet Impact: - spresense:rndis_smp only Testing: - Tested with nxplayer, telnet Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>