scsi: ufs: expose APIs to allow compiling ufs_test as a module

The UFS tests are used for testing the functionality and performance
of the UFS driver. In some of the tests ufs_test uses several scsi
and UFS APIs for getting the disc information and sending UFS
specific commands.
The used APIs should be exposed in order to allow compilation
of ufs_test as a module.

Change-Id: I1263429bd3d5172af3b5552f0b8b503e32a04e51
Signed-off-by: Gilad Broner <gbroner@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>