FROMLIST: ufs: allow host driver to disable wb toggling during clock scaling

Mediatek ufs do not want to toggle write booster during clock scaling.
This patch allow host driver to disable wb toggling during clock scaling.

So, introduce a flag UFSHCD_CAP_WB_WITH_CLK_SCALING to decouple WB
and clock scaling. UFSHCD_CAP_WB_WITH_CLK_SCALING only valid when
UFSHCD_CAP_CLK_SCALING is set. Just like UFSHCD_CAP_HIBERN8_WITH_CLK_GATING
is valid only when UFSHCD_CAP_CLK_GATING set.

Set UFSHCD_CAP_WB_WITH_CLK_SCALING for qcom to compatible legacy design in
the same time.

Bug: 243114290
Link: https://lore.kernel.org/linux-scsi/20220804025422.18803-1-peter.wang@mediatek.com/


[Peter: Resolved minor conflict in drivers/scsi/ufs/ufs-qcom.c,
drivers/scsi/ufs/ufs-sysfs.c, drivers/scsi/ufs/ufshcd.h, drivers/scsi/ufs/ufshcd.c ]
Change-Id: Id58fd6dcbeb63e7567922ddec7e70cd2787bbb6e
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>