USB: ehci tdi : let's tdi_reset set host mode

tdi_reset is already taking care of setting host mode for tdi devices.
Don't duplicate code in platform driver.

Make ehci_halt a nop if the controller is not in host mode (otherwise it 
will fail), and let's ehci_reset do the tdi_reset.
We need to move hcd->has_tt flags before ehci_halt, in order ehci_halt 
knows we are a tdi device.


Before the setup routine was doing :
- put controller in host mode
- ehci_halt
- ehci_init
- hcd->has_tt = 1;
- ehci_reset

Now we do :
- hcd->has_tt = 1;
- ehci_halt
- ehci_init
- ehci_reset

PS : now we handle correctly the device -> host transition.

Signed-off-by: Matthieu CASTET <matthieu.castet@parrot.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>