phy: tegra: xusb: Fix unbalanced regulator disable in UTMI PHY mode

phy: tegra: xusb: Fix unbalanced regulator disable in UTMI PHY mode

When transitioning from USB_ROLE_DEVICE to USB_ROLE_NONE, the code
assumed that the regulator should be disabled. However, if the regulator
is marked as always-on, regulator_is_enabled() continues to return true,
leading to an incorrect attempt to disable a regulator which is not
enabled.

This can result in warnings such as:

[  250.155624] WARNING: CPU: 1 PID: 7326 at drivers/regulator/core.c:3004
_regulator_disable+0xe4/0x1a0
[  250.155652] unbalanced disables for VIN_SYS_5V0

To fix this, we move the regulator control logic into
tegra186_xusb_padctl_id_override() function since it's directly related
to the ID override state. The regulator is now only disabled when the role
transitions from USB_ROLE_HOST to USB_ROLE_NONE, by checking the VBUS_ID
register. This ensures that regulator enable/disable operations are
properly balanced and only occur when actually transitioning to/from host
mode.

Fixes: 49d46e3c7e59 ("phy: tegra: xusb: Add set_mode support for UTMI phy on Tegra186")
Cc: stable@vger.kernel.org
Signed-off-by: Wayne Chang <waynec@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://lore.kernel.org/r/20250502092606.2275682-1-waynec@nvidia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>