drivers: platform: tegra: fix sparse tool warnings

drivers: platform: tegra: fix sparse tool warnings

Fix the following sparse warning:
- drivers/platform/tegra/tegra_usb_pad_ctrl.c:607:6: warning:
symbol 'utmi_phy_pad' was not declared. Should it be static?

utmi_phy_pad() is internal to tegra_usb_pad_ctrl driver
hence it should be declared static.

Bug 200067946

Change-Id: I7e26dd8ec95dd816902db6e14a7270baeef8acb7
Signed-off-by: Rohith Seelaboyina <rseelaboyina@nvidia.com>
Reviewed-on: http://git-master/r/719288
Reviewed-by: Amit Sharma (SW-TEGRA) <amisharma@nvidia.com>
Reviewed-by: Sachin Nikam <snikam@nvidia.com>
Reviewed-on: http://git-master/r/810573
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Ajay Gupta <ajayg@nvidia.com>
Reviewed-by: TW Chiu <twchiu@nvidia.com>
Tested-by: Ajay Gupta <ajayg@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Ashutosh Jha <ajha@nvidia.com>