unify congestion control options

target/linux/ar71xx/config-2.6.29

target/linux/ar71xx/config-2.6.30

target/linux/brcm63xx/config-2.6.27

target/linux/cavium-octeon/config-default

target/linux/cobalt/config-default

target/linux/etrax/config-2.6.30

target/linux/gemini/config-default

target/linux/generic-2.6/config-2.6.21

target/linux/generic-2.6/config-2.6.23

target/linux/generic-2.6/config-2.6.25

target/linux/generic-2.6/config-2.6.27

target/linux/generic-2.6/config-2.6.28

target/linux/generic-2.6/config-2.6.29

target/linux/generic-2.6/config-2.6.30

target/linux/iop32x/config-default

target/linux/ixp4xx/config-2.6.27

target/linux/ixp4xx/config-2.6.28

target/linux/ixp4xx/config-2.6.29

target/linux/ixp4xx/config-2.6.30

target/linux/ixp4xx/config-default