Revert "SBC8548: fix address mask to allow 64M flash"

Revert "SBC8548: fix address mask to allow 64M flash"

This reverts commit ccf1ad535ae1c0dc2d466235c668adbdfe3a55b7.

The commit "SBC8548: fix address mask to allow 64M flash"
essentially made this change:

  * OR6:
- *    Addr Mask = 64M = OR6[0:16] = 1111 1100 0000 0000 0
+ *    Addr Mask = 64M = OR6[0:16] = 1111 1000 0000 0000 0

But this makes no sense, as section 13.3.1.2.1 in the
MPC8548ERM v2 clearly indicates the masks:

	1111_1111_1000_0000_0	8 Mbytes
	1111_1100_0000_0000_0	64 Mbytes
	1111_1000_0000_0000_0	128 Mbytes

So the original value was correct, and the commit was invalid,
causing a 128MB mapping for a 64MB flash device.  The problem
rears its head when trying to configure u-boot to have access
to both flash, since the default memory map is:

	FB80_0000 – FF7F_FFFF 32-bits 64MB FLASH SODIMM
	FF80_0000 – FFFF_FFFF 8-bits 8MB FLASH

By extending the mapping of the 64MB flash to 128MB, it now
conflicts with the normal 8MB boot flash, causing issues.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>