fix(arm_fpga): limit BL31 memory usage

At the moment we specified the BL31 memory limits to 1MB; since we
typically have gigabytes of DRAM, we can be quite generous.

However the default parameters expect the devicetree binary at
0x80070000, so we should actually make sure we have no code or data
beyond that point.

Limit the ARM FPGA BL31 memory footprint to this available 7*64K region.
We stay within the limit at the moment, with more than half of it
reserved for stacks, so this could be downsized later should we run
into problems.

The PIE addresses stay as they are, since the default addresses do not
apply there anywhere, and the build is broken anyway.

Change-Id: I7768af1a93ff67096f4359fc5f5feb66464bafaa
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
1 file changed