powerpc/mpc85xx:Increase binary size for P, B & T series boards.

u-boot binary size for Freescale mpc85xx platforms is 512KB.
This has been reached to upper limit for some of the platforms causig
linker error.

So, Increase the u-boot binary size to 768KB.

Signed-off-by: York Sun <yorksun@freescale.com>
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
31 files changed