tilelink: remove obsolete addr_lo signal (#895)

When we first implemented TL, we thought this was helpful, because
it made WidthWidgets stateless in all cases. However, it put too
much burden on all other masters and slaves, none of which benefitted
from this signal. Furthermore, even with addr_lo, WidthWidgets were
information lossy because when they widen, they have no information
about what to fill in the new high bits of addr_lo.

src/main/scala/tilelink/CacheCork.scala

@@ -79,7 +79,6 @@ class TLCacheCork(unsafe: Boolean = false)(implicit p: Parameters) extends LazyM
       c_d.bits.size    := in.c.bits.size
       c_d.bits.source  := in.c.bits.source
       c_d.bits.sink    := UInt(0)
-      c_d.bits.addr_lo := in.c.bits.address
       c_d.bits.data    := UInt(0)
       c_d.bits.error   := Bool(false)