db-native: unbreak build of 4.3.29

  - adding a patch to db_4.3.29 breaks db-native, which needs the same
  - patch, moved the patch to 'files' since it should work on all versions
  - which require it.

diff --git a/packages/db/db-4.3.29/.mtn2git_empty b/packages/db/files/.mtn2git_empty
similarity index 100%
rename from packages/db/db-4.3.29/.mtn2git_empty
rename to packages/db/files/.mtn2git_empty

diff --git a/packages/db/db-4.3.29/arm-thumb-mutex.patch b/packages/db/files/arm-thumb-mutex.patch
similarity index 100%
rename from packages/db/db-4.3.29/arm-thumb-mutex.patch
rename to packages/db/files/arm-thumb-mutex.patch