Sadly the blue thermal compound on the SOC makes it impossible to identify, the same goes for the WLAN chips with their cans still on.
From a logical point of view though, there is little reason to believe that they've moved away from Broadcom for their second h/w revision. Broadcom, Intel/ lantiq and, to a lesser extent, Mediatek offer xDSL/ FXS/ DECT solutions (aside from some tiny specialist manufacturers). The lantiq VRX2xx generation is a bit towards the end of its lifespan (the SOC is a bit slow and doesn't support profile 35), GRX 3xx and 5xx a bit new and not overly common (AVM is using them in their newer devices), another strategy seems to be combining lantiq modem hardware with QCA SOCs, which aren't supported (modem/ FXS/ DECT) by OpenWrt at the moment either.
Regardless of these theories, it's all guesswork until someone looks under the thermal compound and opens the cans over the WLAN cards.