Fix Truncation warning cpufreq-linux.c->cpufreq_available_governors

limit cpu identifer to 0xFFFF

Change-Id: I6fb170aa7ce32b7b5c0366bbd689878bb5069be8
diff --git a/firmware/target/hosted/cpufreq-linux.c b/firmware/target/hosted/cpufreq-linux.c
index 55a0bf3..d622cf1 100644
--- a/firmware/target/hosted/cpufreq-linux.c
+++ b/firmware/target/hosted/cpufreq-linux.c
@@ -60,7 +60,7 @@
     snprintf(available_governors_interface,
              sizeof(available_governors_interface),
              "/sys/devices/system/cpu/cpu%d/cpufreq/scaling_available_governors",
-             cpu);
+             cpu & 0xFFFF);
 
     FILE *f = open_read(available_governors_interface);
     if(f == NULL)