Flush during hibern8 is sufficient on MediaTek platforms, thus enable
UFSHCI_QUIRK_SKIP_MANUAL_WB_FLUSH_CTRL to skip enabling
fWriteBoosterBufferFlush during WriteBooster initialization.

Link: https://lore.kernel.org/r/20201222072928.32328-1-stanley.chu@mediatek.comReviewed-by: NAvri Altman <avri.altman@wdc.com>
Signed-off-by: NStanley Chu <stanley.chu@mediatek.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>