sun4i-usb: allow USB1.1 devices on OTG USB 2.0 port

When OTG port is USB2.0 type, USB1.1 devices do not work:

[   56.790000] ------------IRQ CONNECT-------------
[   56.790000]
[   56.960000] [sw_hcd]: reset port.
[   57.020000] [sw_hcd]: reset port stopped.
[   57.080000] usb 1-1: new full-speed USB device number 3 using sw_hcd_host0
[   57.080000] usb 1-1: parent hub has no TT
[   57.090000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   57.100000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   57.110000] [sw_hcd]: reset port.
[   57.170000] [sw_hcd]: reset port stopped.
[   57.230000] usb 1-1: new full-speed USB device number 4 using sw_hcd_host0
[   57.230000] usb 1-1: parent hub has no TT
[   57.240000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   57.250000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   57.250000] [sw_hcd]: reset port.
[   57.320000] [sw_hcd]: reset port stopped.
[   57.380000] usb 1-1: new full-speed USB device number 5 using sw_hcd_host0
[   57.380000] usb 1-1: parent hub has no TT
[   57.390000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   57.400000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   57.400000] [sw_hcd]: reset port.
[   57.470000] [sw_hcd]: reset port stopped.
[   57.530000] usb 1-1: new full-speed USB device number 6 using sw_hcd_host0
[   57.530000] usb 1-1: parent hub has no TT
[   57.540000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   57.540000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   57.550000] hub 1-0:1.0: unable to enumerate USB device on port 1

Enabling .has_tt flag on HCD appears to fix or at least workaround the issue:

[   20.960000] ------------IRQ CONNECT-------------
[   20.960000]
[   21.120000] [sw_hcd]: reset port.
[   21.180000] [sw_hcd]: reset port stopped.
[   21.180000] spurious?
[   21.240000] usb 1-1: new full-speed USB device number 2 using sw_hcd_host0
[   21.240000] [sw_hcd]: reset port.
[   21.300000] [sw_hcd]: reset port stopped.
[   21.360000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   21.360000] [sw_hcd]: sw_hcd_h_disable, epnum = 0
[   21.380000] WRN:L1722(drivers/usb/sun4i_usb/hcd/core/sw_hcd_host.c):ERR: sw_hcd_h_ep0_irq, STALLING ENDPOINT
[   21.380000] WRN:L1741(drivers/usb/sun4i_usb/hcd/core/sw_hcd_host.c):ERR: sw_hcd_h_ep0_irq, ep aborting
[   21.390000] WRN:L1722(drivers/usb/sun4i_usb/hcd/core/sw_hcd_host.c):ERR: sw_hcd_h_ep0_irq, STALLING ENDPOINT
[   21.390000] WRN:L1741(drivers/usb/sun4i_usb/hcd/core/sw_hcd_host.c):ERR: sw_hcd_h_ep0_irq, ep aborting
[   21.400000] WRN:L1722(drivers/usb/sun4i_usb/hcd/core/sw_hcd_host.c):ERR: sw_hcd_h_ep0_irq, STALLING ENDPOINT
[   21.400000] WRN:L1741(drivers/usb/sun4i_usb/hcd/core/sw_hcd_host.c):ERR: sw_hcd_h_ep0_irq, ep aborting
[   21.410000] usb 1-1: New USB device found, idVendor=045e, idProduct=0745
[   21.420000] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[   21.420000] usb 1-1: Product: Microsoft\xffffffc2\xffffffae\xffffffae 2.4GHz Transceiver v6.0
[   21.430000] usb 1-1: Manufacturer: Microsoft

Not sure if this is correct or complete fix, as with .has_tt kernel log shows
some warnings. On the other hand, musb uses same flag.

Tested over linux-sunxi-3.4 (+ otg-usb-2.0 patch), compile tested on
linux-sunxi-3.0.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>