lrdp-v2: ftrace: Add ftrace parsing

Use the 'crash' and 'trace-cmd' tools to extract raw
ftrace data and parse out the ftrace buffer. A file
named 'ftrace.txt' is created in the outdir path if
all commands succeed.

Change-Id: I7f1bcfae99b7b9a4ca6dc3550090441318e857e0