usb: phy: remove exported function from __init section

The symbol usb_bind_phy is exported and annotated __init.
It looks like section mismatch. Fix by removing the
__init annotation of usb_bind_phy.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Denis Efremov <yefremov.denis@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>