S7D/S6 : fix dynamic bl2ex size [1/1]

PD#SWPL-178900

Problem:
save blob-bl2e/x.bin for device-sign

Solution:
fixed

Verify:
S7D/S6

Change-Id: I18118fb6d9b5c0c775c406ec203f9a0bec574f30
Signed-off-by: wenbo.wang <wenbo.wang@amlogic.com>
2 files changed