lttng-tools: update to 2.11.0

lttng-tools: update to 2.11.0

Remove 0001-Skip-when-testapp-is-not-present.patch as it is unclear
whether it needs to be rebased, and difficult to rebase.

Remove 0001-check-for-gettid-API-during-configure.patch as it
is no longer needed.

Ptests still seem to run ok, however they are rather slow,
so I did not wait for their completion.

Signed-off-by: Alexander Kanavin <alex.kanavin@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>