Problem:
Linux kernel hangs up when it write a file to NFS mounted directory.
Solution:
Modify bus controller setting for CS4, which connected smsc9221 ethernet
controller.

Detail:
Modify CS4BCR bit[29:28] (IWW[1:0]) from 00 to 01.
Modify CS4BCR bit[20:19] (IWRRD[1:0]) from 00 to 01.
Modify CS4BCR bit[17:16] (IWRRS[1:0]) from 00 to 01.
Modify CS4WCR bit[27:26] (WSW[1:0]) from 10 to 11
Modify CS4WCR bit[25:24] (WHW[1:0]) from 01 to 10
Modify CS4WCR bit[18:16] (WW[2:0]) from 101 to 111
Modify CS4WCR bit[13:11] (SW[2:0]) from 010 to 011
Modify CS4WCR bit[10:7] (WR[3:0]) from 1000 to 1011

Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>