powerpc/B4420: Fixed incomplete handling for 0x9d serdes2

Crossbars and IDT were not getting configured for Serdes2 protocol
0x9d for B4420.

Signed-off-by: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Signed-off-by: Shaveta Leekha <shaveta@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>