phy: exynos5-usbdrd: convert Vbus supplies to regulator_bulk

Using the regulator_bulk APIs, the handling of power supplies becomes
much simpler. There is no need anymore to check if regulators have been
acquired or not, the bulk APIs will do all the work for us. We can also
drop the various handles to the individual power supplies in the driver
runtime data and instead simply treat them all as one thing. Error
cleanup also becomes much simpler.

Converting to the regulator_bulk APIs also makes it easier to add
support for those SoCs that have additional power supplies for the PHY.
Google Tensor gs101 is one example of such a SoC. Otherwise we'd have
to add all additional supplies individually via individual calls to
regulator_get() and enable/disable handle them all individually,
including complicated error handling. That doesn't scale and clutters
the code.

Just update the code to use the regulator_bulk APIs.

Signed-off-by: André Draszik <andre.draszik@linaro.org>
Tested-by: Will McVicker <willmcvicker@google.com>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Tested-by: Peter Griffin <peter.griffin@linaro.org>
Link: https://lore.kernel.org/r/20240617-usb-phy-gs101-v3-5-b66de9ae7424@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>