xics: move registration of global state to realize()

Registration of global state belongs into realize so move it there.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
pseries: Add H_SET_MODE hcall to change guest exception endianness

H_SET_MODE is used for controlling various partition settings. One
of these settings is the endianness a guest takes its exceptions in.

Signed-off-by: Anton Blanchard <anton@samba.org>
[agraf: fix whitespace]
Signed-off-by: Alexander Graf <agraf@suse.de>