powerpc: configs: Fix init_ram physical address for several boards

For e6500 and e5500 SoCs, it was intended to put init_ram address in
ccsr reserved space. It is no longer true since SerDes module took the
space. Move it to another reserved space at CCSR + 0x03c000.

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