xhci: Set slot and ep0 flags for address command.

Matt's AsMedia xHCI host controller was responding with a Context Error
to an address device command after a configured device reset.  Some
sequence of events leads both the slot and endpoint zero add flags
cleared to zero, which the AsMedia host doesn't like:

[  223.701839] xhci_hcd 0000:03:00.0: Slot ID 1 Input Context:
[  223.701841] xhci_hcd 0000:03:00.0: @ffff880137b25000 (virt) @ffffc000 (dma) 0x000000 - drop flags
[  223.701843] xhci_hcd 0000:03:00.0: @ffff880137b25004 (virt) @ffffc004 (dma) 0x000000 - add flags
[  223.701846] xhci_hcd 0000:03:00.0: @ffff880137b25008 (virt) @ffffc008 (dma) 0x000000 - rsvd2[0]
[  223.701848] xhci_hcd 0000:03:00.0: @ffff880137b2500c (virt) @ffffc00c (dma) 0x000000 - rsvd2[1]
[  223.701850] xhci_hcd 0000:03:00.0: @ffff880137b25010 (virt) @ffffc010 (dma) 0x000000 - rsvd2[2]
[  223.701852] xhci_hcd 0000:03:00.0: @ffff880137b25014 (virt) @ffffc014 (dma) 0x000000 - rsvd2[3]
[  223.701854] xhci_hcd 0000:03:00.0: @ffff880137b25018 (virt) @ffffc018 (dma) 0x000000 - rsvd2[4]
[  223.701857] xhci_hcd 0000:03:00.0: @ffff880137b2501c (virt) @ffffc01c (dma) 0x000000 - rsvd2[5]
[  223.701858] xhci_hcd 0000:03:00.0: Slot Context:
[  223.701860] xhci_hcd 0000:03:00.0: @ffff880137b25020 (virt) @ffffc020 (dma) 0x8400000 - dev_info
[  223.701862] xhci_hcd 0000:03:00.0: @ffff880137b25024 (virt) @ffffc024 (dma) 0x010000 - dev_info2
[  223.701864] xhci_hcd 0000:03:00.0: @ffff880137b25028 (virt) @ffffc028 (dma) 0x000000 - tt_info
[  223.701866] xhci_hcd 0000:03:00.0: @ffff880137b2502c (virt) @ffffc02c (dma) 0x000000 - dev_state
[  223.701869] xhci_hcd 0000:03:00.0: @ffff880137b25030 (virt) @ffffc030 (dma) 0x000000 - rsvd[0]
[  223.701871] xhci_hcd 0000:03:00.0: @ffff880137b25034 (virt) @ffffc034 (dma) 0x000000 - rsvd[1]
[  223.701873] xhci_hcd 0000:03:00.0: @ffff880137b25038 (virt) @ffffc038 (dma) 0x000000 - rsvd[2]
[  223.701875] xhci_hcd 0000:03:00.0: @ffff880137b2503c (virt) @ffffc03c (dma) 0x000000 - rsvd[3]
[  223.701877] xhci_hcd 0000:03:00.0: Endpoint 00 Context:
[  223.701879] xhci_hcd 0000:03:00.0: @ffff880137b25040 (virt) @ffffc040 (dma) 0x000000 - ep_info
[  223.701881] xhci_hcd 0000:03:00.0: @ffff880137b25044 (virt) @ffffc044 (dma) 0x2000026 - ep_info2
[  223.701883] xhci_hcd 0000:03:00.0: @ffff880137b25048 (virt) @ffffc048 (dma) 0xffffe8e0 - deq
[  223.701885] xhci_hcd 0000:03:00.0: @ffff880137b25050 (virt) @ffffc050 (dma) 0x000000 - tx_info
[  223.701887] xhci_hcd 0000:03:00.0: @ffff880137b25054 (virt) @ffffc054 (dma) 0x000000 - rsvd[0]
[  223.701889] xhci_hcd 0000:03:00.0: @ffff880137b25058 (virt) @ffffc058 (dma) 0x000000 - rsvd[1]
[  223.701892] xhci_hcd 0000:03:00.0: @ffff880137b2505c (virt) @ffffc05c (dma) 0x000000 - rsvd[2]
...
[  223.701927] xhci_hcd 0000:03:00.0: // Ding dong!
[  223.701992] xhci_hcd 0000:03:00.0: Setup ERROR: address device command for slot 1.

The xHCI spec says that both flags must be set to one for the Address
Device command.  When the device is first enumerated,
xhci_setup_addressable_virt_dev() does set those flags.  However, when
the device is addressed after it has been reset in the configured state,
xhci_setup_addressable_virt_dev() is not called, and
xhci_copy_ep0_dequeue_into_input_ctx() is called instead.  That function
relies on the flags being set up by previous commands, which apparently
isn't a good assumption.

Move the setting of the flags into the common parent function.

This should be queued for stable kernels as old as 2.6.35, since that
was the first introduction of xhci_copy_ep0_dequeue_into_input_ctx.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Matt <mdm@iinet.net.au>
Cc: stable@vger.kernel.org