build(bl31): support separated memory for RW DATA

Update linker file and init codes to allow using separated
memory region for RW DATA. Init codes will copy the RW DATA
from the image to the linked address.

On some NXP platforms, after the BL31 image has been verified,
the bl31 image space will be locked/protected as RO only, so
need to move the RW DATA and NOBITS out of the bl31 image.

Signed-off-by: Ye Li <ye.li@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: I361d9a715890961bf30790a3325f8085a40c0c39
4 files changed