This patch fixes shared library compilation due to undefined
reference to an exported variable 'bbdev_logtype'.
Fixes: 4935e1e9f76e ("bbdev: introduce wireless base band device lib")
Fixes: b8cfe2c9aed2 ("bb/turbo_sw: add software turbo driver")
Fixes: 7dc2b1589440 ("bb/null: add null base band device driver")
Signed-off-by: Amr Mokhtar <amr.mokhtar@intel.com>
dd21615819