rootfs: add msr-tools package

Add the `msr-tools` package which provides binaries to read/write MSRs.
We'll use this package to test MSRs exposed in the Guest.

Signed-off-by: Alexandru-Cezar Sardan <alsardan@amazon.com>

Author: Alexandru-Cezar Sardan

resources/tests/setup_rootfs.sh

@@ -11,7 +11,7 @@ prepare_fc_rootfs() {
     SSH_DIR="$BUILD_DIR/ssh"
     RESOURCE_DIR="$2"
 
-    packages="udev systemd-sysv openssh-server iproute2"
+    packages="udev systemd-sysv openssh-server iproute2 msr-tools"
     apt-get update
     apt-get install -y --no-install-recommends $packages