ARM: dts: aspeed: rainier,everest: Move reserved memory regions

ARM: dts: aspeed: rainier,everest: Move reserved memory regions

Move the reserved regions to account for a decrease in DRAM when ECC is
enabled. ECC takes 1/9th of memory.

Running on HW with ECC off, u-boot prints:
DRAM:  already initialized, 1008 MiB (capacity:1024 MiB, VGA:16 MiB, ECC:off)

And with ECC on, u-boot prints:
DRAM:  already initialized, 896 MiB (capacity:1024 MiB, VGA:16 MiB, ECC:on, ECC size:896 MiB)

This implies that MCR54 is configured for ECC to be bounded at the
bottom of a 16MiB VGA memory region:

1024MiB - 16MiB (VGA) = 1008MiB
1008MiB / 9 (for ECC) = 112MiB
1008MiB - 112MiB = 896MiB (available DRAM)

The flash_memory region currently starts at offset 896MiB:
0xb8000000 (flash_memory offset) - 0x80000000 (base memory address) = 0x38000000 = 896MiB

This is the end of the available DRAM with ECC enabled and therefore it
needs to be moved.

Since the flash_memory is 64MiB in size and needs to be 64MiB aligned,
it can just be moved up by 64MiB and would sit right at the end of the
available DRAM buffer.

The ramoops region currently follows the flash_memory, but it can be
moved to sit above flash_memory which would minimize the address-space
fragmentation.

Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20220916195535.1020185-1-anoo@linux.ibm.com
Signed-off-by: Joel Stanley <joel@jms.id.au>