scsi: ufs-mediatek: Add missing MODULE_* information

When building the ufs-mediatek module the following warning shows up:

WARNING: modpost: missing MODULE_LICENSE() in
  drivers/scsi/ufs/ufs-mediatek.o

Rework to add MODULE_LICENSE,MODULE_AUTHOR and MODULE_DESCRIPTION.

Fixes: ddd90623

 ("scsi: ufs-mediatek: Add UFS support for Mediatek SoC chips")
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>