phy: exynos5-usbdrd: s/FIELD_PREP_CONST/FIELD_PREP where appropriate

phy: exynos5-usbdrd: s/FIELD_PREP_CONST/FIELD_PREP where appropriate

Commit 9b6662a0f715 ("phy: exynos5-usbdrd: use GENMASK and FIELD_PREP
for Exynos5 PHY registers") added FIELD_PREP_CONST() in many cases
where FIELD_PREP() would have been more appropriate. It also switched
existing uses of FIELD_PREP() to FIELD_PREP_CONST().

FIELD_PREP() is the preferred macro to use whenever possible while
FIELD_PREP_CONST() is meant to be used in constant initialisers.

Switch (back) to FIELD_PREP().

Fixes: 7e6c2ffe6c22 ("phy: exynos5-usbdrd: convert some FIELD_PREP_CONST() to FIELD_PREP()")
Signed-off-by: André Draszik <andre.draszik@linaro.org>
Link: https://lore.kernel.org/r/20250429-exynos5-phy-field-prep-v1-2-39eb279a3e0e@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>