scsi: ufs: ufs-mediatek: Fix HCI version in some platforms

Some MediaTek SoC platforms with UFSHCI version below 3.0 have incorrect
UFSHCI versions showed in register map.

Fix the version by referring to UniPro version which is always correct.

Link: https://lore.kernel.org/r/20210531062642.12642-1-stanley.chu@mediatek.com
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>