MLK-14599-1 soc:imx8:Update SCFW API

MLK-14599-1 soc:imx8:Update SCFW API

Update SCFW API to the following commit in SCFW git:
"
'commit: ("a620caf7444c45715b68b5cf128219005598365f")'
Author: Mike <michael.kjar@nxp.com>
Date:   Thu Mar 30 18:35:27 2017 -0500

Added a DDR Stress Test to the test folder

- New DDR test is like the stress test where we increment/sweep the DDR freq
- More tests may be added as development continues
- Modified mx8qm/soc.h to boot the A72 to DDR when building with option qmddr
"

Signed-off-by: Ranjani Vaidyanathan <Ranjani.Vaidyanathan@nxp.com>