ARM: mvebu: define crypto SRAM ranges in armada-375-db.dts

Define the crypto SRAM ranges so that the resources referenced by the
sa-sram node can be properly extracted from the DT.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>