UBUNTU: SAUCE: arm64: arch_timer: Add erratum handler for globally defined capability

UBUNTU: SAUCE: arm64: arch_timer: Add erratum handler for globally defined capability

BugLink: https://bugs.launchpad.net/bugs/1675509
Should we ever have a workaround for an erratum that is detected using
a capability (and affecting the whole system), it'd be nice to have
a way to probe them directly.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit b50b1f54abc59e7f4913b9bf476c6e89259776b7
 in the timers/errata-rework branch of
 git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git)
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>