[arch][arm64] use SMC when booted at EL2 in QEMU

If we were booted at EL2 (e.g. when passing -machine
virt,virtualization=on), we need to use SMC instead of HVC for PSCI
calls. Change psci_call() to do this and add a flag to do-qemuarm to
allow testing this scenario.

scripts/do-qemuarm

@@ -12,6 +12,7 @@ function HELP {
     echo "-d a virtio display"
     echo "-3 cortex-m3 based platform"
     echo "-6 64bit arm"
+    echo "-v boot kernel at EL2"
     echo "-m <memory in MB>"
     echo "-s <number of cpus>"
     echo "-h for help"
@@ -23,6 +24,7 @@ DO_NET=0
 DO_NET_TAP=0
 DO_BLOCK=0
 DO_64BIT=0
+DO_VIRT=0
 DO_CORTEX_M3=0
 DO_DISPLAY=0
 DO_CMPCTMALLOC=0
@@ -32,7 +34,7 @@ MEMSIZE=512
 SUDO=""
 PROJECT=""
 
-while getopts bdhm:cMnt36p:s: FLAG; do
+while getopts bdhm:cMnt36vp:s: FLAG; do
     case $FLAG in
         b) DO_BLOCK=1;;
         c) DO_CMPCTMALLOC=1;;
@@ -42,6 +44,7 @@ while getopts bdhm:cMnt36p:s: FLAG; do
         t) DO_NET_TAP=1;;
         3) DO_CORTEX_M3=1;;
         6) DO_64BIT=1;;
+        v) DO_VIRT=1;;
         m) MEMSIZE=$OPTARG;;
         s) SMP=$OPTARG;;
         p) PROJECT=$OPTARG;;
@@ -58,6 +61,9 @@ if [ $DO_64BIT == 1 ]; then
     QEMU="qemu-system-aarch64"
     CPU="cortex-a53"
     MACHINE="virt"
+    if [ $DO_VIRT == 1 ]; then
+      MACHINE+=",virtualization=on"
+    fi
     _PROJECT="qemu-virt-arm64-test"
 elif [ $DO_CORTEX_M3 == 1 ]; then
     QEMU="qemu-system-arm"