usb: tegra: ULPI regression on tegra20

Trying to enumerate USB devices connected via ULPI to T20 failed as
follows:

USB2:   ULPI integrity check failed

Git bisecting revealed the following commit being at odds:

commit 2d34151f
usb: tegra: refactor PHY type selection

Looking at above commit one quickly identifies a copy paste error which
this patch fixes. Happy ULPIing again (;-p).

Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>