samplicator: update to latest master commit 2021-10-11

samplicator: update to latest master commit 2021-10-11

The newest master branch has important fixes. However, no new release is
published [0]. Switch to git and update to latest master commit.
This introduces new version scheme by using YYYY-MM-DD of the commit.

In addition, add necessary "PKG_FIXUP" and "PKG_REMOVE_FILES" to allow
compile the new version. Also add enable "PKG_BUILD_PARALLEL".

Further, use a pidfile and remove outdated patches.

https://github.com/sleinen/samplicator/issues/73

Signed-off-by: Nick Hainke <vincent@systemli.org>
(cherry picked from commit a6d7ed4d6d77ca27ba60e763f0ef8aee4faf372b)