ANDROID: scsi: ufs: export ufshcd_wb_ctrl func

At mainline can not disable after enable write booster.
Continued enablement of the write booster affects ufs life expectancy.
And there is also a problem with power efficiency.
So modified ufshcd_wb_ctrl for dynamic enable at other driver.

Bug: 163991865

Change-Id: Iad0734d29229841bf583f7befbf35a769d3c2478
Signed-off-by: SEO HOYOUNG <hy50.seo@samsung.com>