phy: tegra: Select USB_COMMON for usb_get_maximum_speed()

The usb_get_maximum_speed() function is part of the usb-common module,
so enable it by selecting the corresponding Kconfig symbol.

While at it, also make sure to depend on USB_SUPPORT because USB_PHY
requires that. This can lead to Kconfig conflicts if USB_SUPPORT is not
enabled while attempting to enable PHY_TEGRA_XUSB.
Reported-by: kbuild test robot <lkp@intel.com>
Suggested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200330101038.2422389-1-thierry.reding@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/phy/tegra/Kconfig

 # SPDX-License-Identifier: GPL-2.0-only
 config PHY_TEGRA_XUSB
 	tristate "NVIDIA Tegra XUSB pad controller driver"
-	depends on ARCH_TEGRA
+	depends on ARCH_TEGRA && USB_SUPPORT
+	select USB_COMMON
 	select USB_CONN_GPIO
 	select USB_PHY
 	help