kernel: switch openwrt default to TCP cubic from westwood (patch by Dave Täht)

Despite Westwood's theoretical advantages, in nearly
every benchmark we ran last year, TCP cubic won, whether it be
on correct RTT estimates, amount of buffering, responsiveness,
etc. on current hardware and software designs.

(both need timestamps on to work well, besides)

TCP cubic is better maintained and understood than westwood,
also.

While a scenario where westwood would win possibly exists,
there is too much buffering in the wifi stack in particular
at present, to see any improvement.

If you wish to exercise various TCPs under contention,
the current svn head of netperf (2.6) has options to switch
congestion control agorithms on the fly, as does iperf.

SVN-Revision: 32514

target/linux/generic/config-3.3

@@ -575,8 +575,8 @@ CONFIG_DEFAULT_MMAP_MIN_ADDR=4096
 # CONFIG_DEFAULT_RENO is not set
 CONFIG_DEFAULT_SECURITY=""
 CONFIG_DEFAULT_SECURITY_DAC=y
-CONFIG_DEFAULT_TCP_CONG="westwood"
-CONFIG_DEFAULT_WESTWOOD=y
+CONFIG_DEFAULT_TCP_CONG="cubic"
+CONFIG_DEFAULT_CUBIC=y
 CONFIG_DEFCONFIG_LIST="/lib/modules/$UNAME_RELEASE/.config"
 # CONFIG_DEPRECATED_PARAM_STRUCT is not set
 # CONFIG_DETECT_HUNG_TASK is not set
@@ -2876,7 +2876,7 @@ CONFIG_SYSVIPC_SYSCTL=y
 # CONFIG_TCIC is not set
 CONFIG_TCP_CONG_ADVANCED=y
 # CONFIG_TCP_CONG_BIC is not set
-# CONFIG_TCP_CONG_CUBIC is not set
+CONFIG_TCP_CONG_CUBIC=y
 # CONFIG_TCP_CONG_HSTCP is not set
 # CONFIG_TCP_CONG_HTCP is not set
 # CONFIG_TCP_CONG_HYBLA is not set
@@ -2885,7 +2885,7 @@ CONFIG_TCP_CONG_ADVANCED=y
 # CONFIG_TCP_CONG_SCALABLE is not set
 # CONFIG_TCP_CONG_VEGAS is not set
 # CONFIG_TCP_CONG_VENO is not set
-CONFIG_TCP_CONG_WESTWOOD=y
+# CONFIG_TCP_CONG_WESTWOOD is not set
 # CONFIG_TCP_CONG_YEAH is not set
 # CONFIG_TCP_MD5SIG is not set
 # CONFIG_TEHUTI is not set