Remove assert on buffer address equal zero.
Marvell uses address 0x0 for loading BL33,
so this check is irrelevant and breaks the
debug builds on Marvell platforms.

Change-Id: Ie56a51138e2e4ddd8986dd7036797dc2d8b10125
Signed-off-by: Haim Boot <hayim@marvell.com>
Signed-off-by: Konstantin Porotchkin <kostap@marvell.com>
Reviewed-on: http://vgitil04.il.marvell.com:8080/54589