hikey960:Corrected erroneous DDR_SIZE
hikey960:Corrected erroneous DDR_SIZE

Change-Id: I7194a9a5f0e41308eb3242d20c0d3434f72da591
Signed-off-by: Joel Hutton <dd4a22c4cf7172da81944b53f2d07b1b34bde0cc@Arm.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware