Example to demonstrate usage of `mbed_stats_cpu_get()` API usage

Revision:
22:603552270466
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/cpu-stats.log	Mon May 13 20:02:06 2019 +0100
@@ -0,0 +1,19 @@
+Uptime\s+Idle Time\s+Sleep time\s+DeepSleep time
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
+\d+\s+\d+\s+\d+\s+\d+
\ No newline at end of file