selftests/ir: fix build with ancient kernel headers

Since commit e2bcbd77 ("tools headers UAPI: remove stale lirc.h"),
the build of the selftests fails on rhel 8 since its version of
/usr/include/linux/lirc.h has no definition of RC_PROTO_RCMM32, etc [1].

[1] https://lkml.org/lkml/2022/1/28/275



Fixes: e2bcbd77 ("tools headers UAPI: remove stale lirc.h")
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>