Workaround for Neoverse N1 erratum 1275112

Workaround for Neoverse N1 erratum 1275112

Neoverse N1 erratum 1275112 is a Cat B erratum [1],
present in older revisions of the Neoverse N1 processor core.
The workaround is to set a bit in the implementation defined
CPUACTLR_EL1 system register, which delays instruction fetch after
branch misprediction.

[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.pjdoc-466751330-10325/index.html

Change-Id: If7fe55fe92e656fa6aea12327ab297f2e6119833
Signed-off-by: Lauren Wehrmeister <lauren.wehrmeister@arm.com>