Revert "bus: mvebu-mbus: make sure SDRAM CS for DMA don't overlap the MBus bridge window"

This reverts commit 1737cac6 ("bus: mvebu-mbus: make sure SDRAM CS
for DMA don't overlap the MBus bridge window"), because it breaks DMA
on platforms having more than 2 GB of RAM.

This commit changed the information reported to DMA masters device
drivers through the mv_mbus_dram_info() function so that the returned
DRAM ranges do not overlap with I/O windows.

This was necessary as a preparation to support the new CESA Crypto
Engine driver, which will use DMA for cryptographic operations. But
since it does DMA with the SRAM which is mapped as an I/O window,
having DRAM ranges overlapping with I/O windows was problematic.

To solve this, the above mentioned commit changed the mvebu-mbus to
adjust the DRAM ranges so that they don't overlap with the I/O
windows. However, by doing this, we re-adjust the DRAM ranges in a way
that makes them have a size that is no longer a power of two. While
this is perfectly fine fo...