Block Diagrams: FMComms2 : Add a missing gain block in the digital Rx chain.
                           Add some colour to the Rx and Tx paths.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Block Diagrams : FMCOMMS2 :
  - Change "CTRL In/Out" to only "CTRL".
      - This block now covers ENSM, Control In, and Control Out.
        This is a little easier, because the Control In pin can be
        wrapped into AGC. And TXNRX and ENABLE aren’t always tied to ENSM,
        in FDD Independent they control the transceiver chains separately
        from the ENSM. CTRL seems generic enough to cover all configurations.