fip: add bl31/bl32 top directory [2/2]

PD#SWPL-123810

Problem:
bl31/bl32 too many directories

Solution:
add bl31/bl32 top directory in bootloader

Verify:
compile pass in local

Change-Id: I32ade2176e6a88d92ed9847cba5157ae391b5c12
Signed-off-by: Meng yu <meng.yu@amlogic.com>
29 files changed