scsi: ufs: renesas: Add reusable functions

Since some settings can be reused on other UFS controller (R-Car S4-8
ES1.2), add reusable functions.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/446d67b751a96645799de3aeefec539735aa78c8.1741179611.git.geert+renesas@glider.be


Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>