phy: Return success from generic_setup_phy() when phy is not found

phy: Return success from generic_setup_phy() when phy is not found

Restore the old behavior of ehci_setup_phy() and ohci_setup_phy() to
return success when generic_phy_get_by_index() return -ENOENT.

Fixes: 84e561407a5f ("phy: Add generic_{setup,shutdown}_phy() helpers")
Fixes: 10005004db73 ("usb: ohci: Make usage of generic_{setup,shutdown}_phy() helpers")
Fixes: 083f8aa978a8 ("usb: ehci: Make usage of generic_{setup,shutdown}_phy() helpers")
Fixes: 75341e9c16aa ("usb: ehci: Remove unused ehci_{setup,shutdown}_phy() helpers")
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>