selftests/ftrace: Add dynamic events argument limitation test case

Add argument limitation test case for dynamic events.
This is a boudary check for the maximum number of the probe
event arguments.

Link: https://lore.kernel.org/all/174055078295.4079315.14702008939511417359.stgit@mhiramat.tok.corp.google.com/



Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>