lttng-modules: Fix build failure for 5.10.119+ and 5.15.44+ kernel

The following kernel commit has been back ported to v5.10.119 and v5.15.44.

commit 14c174633f349cb41ea90c2c0aaddac157012f74
Author: Jason A. Donenfeld <Jason@zx2c4.com>
Date:   Thu Feb 10 16:40:44 2022 +0100

  random: remove unused tracepoints

  These explicit tracepoints aren't really used and show sign of aging.
  It's work to keep these up to date, and before I attempted to keep them
  up to date, they weren't up to date, which indicates that they're not
  really used. These days there are better ways of introspecting anyway.

Which causes the following build failure
lttng-modules-2.13.3/src/probes/lttng-probe-random.c:18:10: fatal error: trace/events/random.h: No such file or directory
|    18 | #include <trace/events/random.h>
|       |          ^~~~~~~~~~~~~~~~~~~~~~~
| compilation terminated.

Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>