The DDR memory from 0x88000000 to 0x8FFFFFFF is assigned to M4 on
QM and QXP. The M4 can allocate this memory by two ways,
in SCD or u-boot.
In this patch, u-boot addes the memory reserve node to DTB to pass
the info to kernel, no matter the M4 memory is reserved in SCD
or u-boot. So kernel won't access M4 reserved memory.
Signed-off-by: Peng Fan <peng.fan@nxp.com>