tcl: fix sqlite usage

tcl: fix sqlite usage

- Remove the bundled sqlite unconditionally, as we always want to use
  the external sqlite.
- Remove the --with-system-sqlite option as is only valid for the
  bundled sqlite configure script which we will no longer use.
- Do not remove TDBC when BR2_PACKAGE_SQLITE is not selected as it may
  be used for other TDBC drivers such as MySQL or PostgreSQL.

Fixes:
  http://autobuild.buildroot.net/results/022/02296f8624d3406a63d3a179f53862f245c56dc1/

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>