plat: marvell: armada: a3k: Do not use 'echo -e' in Makefile

It does not have to be supported by the current shell used in Makefile.
Replace it by a simple echo with implicit newline.

Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: I97fe44986ac36d3079d5258c67f0c9184537e7f0
1 file changed