Some changes of TLB entry setting for MPC8572DS

- Move the TLB entry of PIXIS_BASE from TLB0 to TLB1[8], because in CAMP mode,
all the TLB0 entries will be invalidated after cpu1 brings up kernel, thus cpu0
can not access PIXIS_BASE anymore (any access will cause DataTLBError exception)

- Set CONFIG_SYS_DDR_TLB_START to 9 for MPC8572DS board.

Signed-off-by: Haiying Wang <Haiying.Wang@freescale.com>