phy: exynos5-usbdrd: convert udelay() to fsleep()

phy: exynos5-usbdrd: convert udelay() to fsleep()

The timers-howto recommends using usleep_range() and friends anytime
waiting for >= ~10us is required. Doing so can help the timer subsystem
a lot to coalesce wakeups.

Additionally, fsleep() exists as a convenient wrapper so we do not have
to think about which exact sleeping function is required in which case.

Convert all udelay() calls in this driver to use fsleep() to follow the
recommendataion.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://lore.kernel.org/r/20240507-samsung-usb-phy-fixes-v1-2-4ccba5afa7cc@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>