Use the FIELD_PREP() helper, instead open-coding the same operation.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://msgid.link/r/15edeaa9a644c4025234088da3dabb023fce04ac.1708002503.git.geert+renesas@glider.beSigned-off-by: Mark Brown <broonie@kernel.org>