powerpc/srio-pcie-boot: Adjust addresses for SRIO/PCIE boot

The new 768KB u-boot image size requires changes for
SRIO/PCIE boot. These addresses need to be updated to
appropriate locations.

The updated addresses are used to configure the SRIO/PCIE
inbound windows for the boot, and they must be aligned
with the window size based on the SRIO/PCIE modules requirement.
So for the 768KB u-boot image, the inbound window cannot be set
with 0xfff40000 base address and 0xc0000 size, it should be
extended to 1MB size and the base address can be aligned with
the size.

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