init: add missing sync_icache after exception vector patching
init: add missing sync_icache after exception vector patching

There are two cases where sync_icache is not called immediately
after instructions are modified.

Signed-off-by: Nicholas Piggin <24829078df5003d9dd1dd871ca2aeb0b1cf95ef4@gmail.com>
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.vnet.ibm.com>

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