usb: phy: tegra: Avoid use of sizeof(void)

commit 9ce9ec95 upstream.

The PHY configuration is stored in an opaque "config" field, but when
allocating the structure, its proper size needs to be known. In the case
of UTMI, the proper structure is tegra_utmip_config of which a local
variable already exists, so we can use that to obtain the size from.

Fixes the following warning from the sparse checker:

	drivers/usb/phy/phy-tegra-usb.c:882:17: warning: expression using sizeof(void)

Fixes: 81d5dfe6 (usb: phy: tegra: Read UTMIP parameters from device tree)
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/phy/phy-tegra-usb.c

@@ -881,8 +881,8 @@ static int utmi_phy_probe(struct tegra_usb_phy *tegra_phy,
 		return -ENOMEM;
 	}
 
-	tegra_phy->config = devm_kzalloc(&pdev->dev,
-		sizeof(*tegra_phy->config), GFP_KERNEL);
+	tegra_phy->config = devm_kzalloc(&pdev->dev, sizeof(*config),
+					 GFP_KERNEL);
 	if (!tegra_phy->config) {
 		dev_err(&pdev->dev,
 			"unable to allocate memory for USB UTMIP config\n");