Add run_qemu.sh option to append to kernel command line

Will be useful for boot test.

Test: manually invoke run_test.sh, check /proc/cmdline of host
Change-Id: I7a322b59ed6977242f383e30bd1ff0a9d2c45df8
diff --git a/aarch64/run_qemu.sh b/aarch64/run_qemu.sh
index 31e44fa..0920b3f 100755
--- a/aarch64/run_qemu.sh
+++ b/aarch64/run_qemu.sh
@@ -46,7 +46,7 @@
 Usage: $0 [-h] [-v] [-K]
        [-e QEMU] [-L ROM_DIR] [-k KERNEL] [-r ROOTFS] [-R DRIVE] [-F FIRMWARE]
        [-c CPU] [-s NUM_CPUS] [-m MEM] [-g GIC] [-m KVM_MODE] [-G]
-       [-t TIMEOUT]
+       [-t TIMEOUT] [-a APPEND]
 
     -h    output this help text
     -v    print invoked command
@@ -61,6 +61,7 @@
     -m    amount of memory in MB (defaults to ${DEFAULT_RAM})
     -g    version of GIC (defaults to ${DEFAULT_GIC})
     -m    KVM mode (defaults to 'pkvm', other: 'vhe', 'nvhe')
+    -a    append to kernel command line
     -G    enable debugging of emulated system with GDB
     -t    kill QEMU after given number of seconds
     -K    keep temp files
@@ -122,7 +123,7 @@
 APPEND=()
 EXTRA_RO_MOUNTS=()
 
-while getopts ":e:L:k:r:R:F:c:s:m:g:t:M:vGKh" OPT; do
+while getopts ":e:L:k:r:R:F:c:s:m:g:t:M:a:vGKh" OPT; do
 	case "${OPT}" in
 	e)	QEMU="${OPTARG}"		;;
 	L)	ROM_DIR="${OPTARG}"		;;
@@ -136,6 +137,7 @@
 	g)	GIC="${OPTARG}"			;;
 	t)	TIMEOUT="${OPTARG}"		;;
 	M)	MODE="${OPTARG}"		;;
+	a)	APPEND+=("${OPTARG}")		;;
 	v)	VERBOSE=1			;;
 	G)	GDB=1				;;
 	K)	KEEP_TEMP=1			;;