hw/xscom: Reset XSCOM engine after querying sleeping core FIR
hw/xscom: Reset XSCOM engine after querying sleeping core FIR

XSCOM engine blocks subsequently after querying FIR of any
sleeping core. This causes subsequent XSCOM opertions to hang
forever due to XSCOM engine being continuously busy. Reset XSCOM
engine after querying FIR of any sleeping core.

Signed-off-by: Vipin K Parashar <f7dae5427b3dec859a8db9747c62b0d6fc100992@linux.vnet.ibm.com>
Signed-off-by: Vaidyanathan Srinivasan <c012decff9dffda4c10860ab2ba9eb53320d90bc@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

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