powerpc/mpc85xx:Enable debugger support to missed e500v2 SoC

powerpc/mpc85xx:Enable debugger support to missed e500v2 SoC

Freescale's e500v1 and e500v2 cores (used in mpc85xx chips) have some
restrictions on external debugging (JTAG). Need to define define
CONFIG_SYS_PPC_E500_DEBUG_TLB to enable a temporary TLB entry to be
used during boot to work around the limitations.

Enable missed e500v2 SoC i.e. MPC8536, MPC8544, MPC8548 and MPC8572 for
debug support.

Signed-off-by: Radu Lazarescu <radu.lazarescu@freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Cc: Tang Yuantian <Yuantian.Tang@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>