plat: marvell: ap807: use correct address for MCIx4 register

The AP807 uses different register offset for MCIx4 register, reflect it
in the code.

Change-Id: Ic7e44fede3c69083e8629741e7c440b1ae08c35f
Signed-off-by: Grzegorz Jaszczyk <jaz@semihalf.com>
1 file changed