S7: PXP Bringup Bootloader BL30 code portinig [1/3]

PD#SWPL-131338

Problem:
S7 PXP Bringup Bootloader BL30.

Solution:
Code porting from s4

Verify:
Test in S7 PXP.

Change-Id: Ie7aa1acacbbaaa2af42573f7130c2f0929cb9318
Signed-off-by: bangzheng.liu <bangzheng.liu@amlogic.com>
17 files changed