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Further, use a pidfile and remove outdated patches.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>