powerpc/xive: Change IRQ domain to a tree domain
Bugzilla: http://bugzilla.redhat.com/2008723
Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=42054335
Upstream Status: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/
Tested: Tested in a RHEL9 guest running in a Power9 RHEL8.6 host
Signed-off-by: Greg Kurz gkurz@redhat.com