Cortex A77 erratum 1791578 is a Cat B erratum present in r0p0, r1p0,
and r1p1 of the A77 processor core, it is still open.

SDEN can be found here:
https://documentation-service.arm.com/static/60a63a3c982fc7708ac1c8b1

Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: Ib4b963144f880002de308def12744b982d3df868