SerialInterfaceWidth is not actually configurable

src/main/scala/example/Configs.scala

@@ -50,7 +50,6 @@ class WithSimNetwork extends Config((site, here, up) => {
 })
 
 class BaseExampleConfig extends Config(
-  new WithSerialAdapter ++
   new freechips.rocketchip.chip.DefaultConfig)
 
 class DefaultExampleConfig extends Config(

src/main/scala/tlserdes/Configs.scala

@@ -1,7 +1,6 @@
 package tlserdes
 
 import freechips.rocketchip.config.{Parameters, Config}
-import testchipip.WithSerialAdapter
 
 class WithTLSerdes extends Config((site, here, up) => {
   case TLSerdesWidth => 16
@@ -9,7 +8,6 @@ class WithTLSerdes extends Config((site, here, up) => {
 
 class DefaultSerdesConfig extends Config(
   new WithTLSerdes ++
-  new WithSerialAdapter ++
   new freechips.rocketchip.chip.DefaultConfig)
 
 class WithTwoMemChannels extends example.WithTwoMemChannels