Having the definitions of {__,}tls_driver_ctx() under an #if
guard means code referencing them also needs to rely on the
preprocessor. The protection doesn't appear needed so make the
definitions unconditional.

Fixes: db37bc17 ("net/funeth: add the data path")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Dimitris Michailidis <dmichail@fungible.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>