usb: phy-tegra-usb.c: wrong pointer check for remap UTMI

A wrong pointer was used to test the result of devm_ioremap()
Acked-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Chris Ruehl <chris.ruehl@gtsys.com.hk>
Acked-by: Venu Byravarasu <vbyravarasu@nvidia.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>