xive: Add locking to some API calls
xive: Add locking to some API calls

The interrupt allocation calls might happen from threaded inits
and the EQ management can happen from Linux. The underlying cache
management will require mutual exclusion.

Signed-off-by: Benjamin Herrenschmidt <a7089bb6e7e92505d88aaff006cbdd60cc9120b6@kernel.crashing.org>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

open-power/skiboot,open-power/skiboot,legoater/skiboot,stewart-ibm/skiboot,shenki/skiboot,qemu/skiboot,legoater/skiboot,stewart-ibm/skiboot,legoater/skiboot,qemu/skiboot,qemu/skiboot,shenki/skiboot,stewart-ibm/skiboot,shenki/skiboot,open-power/skiboot,open-power/skiboot,mikey/skiboot,legoater/skiboot,legoater/skiboot,mikey/skiboot,shenki/skiboot,qemu/skiboot,shenki/skiboot,open-power/skiboot,mikey/skiboot,qemu/skiboot