board/b4860qds: Add support for configuring SerDes1 Refclks

1) Add support in B4860 board files for using IDT driver where
   IDT8T49N222A is a low phase noise Frequency Translator / Synthesizer
   that generate different refclks for SerDes modules, used this driver
   for reconfiguring SerDes1 Refclks(based on SerDes1 protocols)
   for CPRI to work. CPRI works on 122.88MHz and default refclks coming
   on board are not suitable for it
2) Move SerDes1 refclk1 source selection from eth_b4860qds.c file
   to b4860qds board file, as SerDes1 Refclk1 would come from
   PHY MUX in case of certain protocols, that have been checked here.
   This change would make on board SGMIIs to work
3) Add I2C addresses for IDT8T49N222A devices in board/include file
4) Add define for PCA-I2C bus multiplexer, on which IDT devices exist

Signed-off-by: Shaveta Leekha <shaveta@freescale.com>
Acked-by: York Sun <yorksun@freescale.com>