powerpc/mpc85xx: Add workaround to enable TDM on T1040

powerpc/mpc85xx: Add workaround to enable TDM on T1040

This is a workaround for 32 bit hardware limitation of TDM.
T1040 has 36 bit physical addressing, TDM DMAC register
are 32 bit wide but need to store address of CCSR space
which lies beyond 32 bit address range. This workaround
creats a LAW to enable access of TDM DMA to CCSR by
mapping CCSR to overlap with DDR.
A hole of 16M is created in memory using device tree. This
workaround law is set only if "tdm" is defined in hwconfig.
Also disable POST tests and add LIODN for TDM

Signed-off-by: Sandeep Singh <Sandeep@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>