qt4: Explicitly disable sqlite2

qt4: Explicitly disable sqlite2

* notice that this disables only sqlite2 (sqlite dependency),
  sqlite (sqlite3 dependency) stays enabled

* fixes these errors detected by test-dependencies.sh:
  qt4-embedded/qt4-embedded-plugin-sqldriver-sqlite2/latest doesn't exist
  qt4-embedded/qt4-embedded-plugin-sqldriver-sqlite2-dbg/latest doesn't exist
  qt4-x11-free/qt4-plugin-sqldriver-sqlite2/latest doesn't exist
  qt4-x11-free/qt4-plugin-sqldriver-sqlite2-dbg/latest doesn't exist

(From OE-Core rev: 279c221d9dfce43254ed1f03cf84ea454cc7b485)

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>