Merge changes from topic "bk/gicv5_full"

* changes:
  refactor(gic): unify SGI exception data
  fix(gic): don't access a GIC register if it's not supported
  refactor(gic): add a is_feat_gic_supported() standard helper
  refactor(gic): make the GIC driver generic
  refactor(gic): prepare for a new GIC revision