fix(errata): workaround for Cortex-A710 erratum 2267065

Cortex-A710 erratum 2267065 is a Cat B erratum that applies to
revisions r0p0, r1p0 and r2p0 of the CPU. It is fixed in r2p1.
The workaround is to set CPUACTLR_EL1[22] to 1'b1. Setting
CPUACTLR_EL1[22] will cause the CFP instruction to invalidate
all branch predictor resources regardless of context.

SDEN can be found here:
https://developer.arm.com/documentation/SDEN1775101/latest



Signed-off-by: Bipin Ravi <bipin.ravi@arm.com>
Change-Id: Ia9085aaf9b2b6a2b25d03ab36bd3774839fac9aa