USB: ehci-platform: support EHCIs with transaction translator

Some EHCI controllers have a Transaction Translator built into
the root hub. Support this feature in device tree when using
the ehci-platform driver by adding a feature flag for it.

This is needed to get USB working on NXP LPC18xx/43xx platforms.

Signed-off-by: Joachim Eastwood <[e-mail]>
Acked-by: Alan Stern <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/usb/usb-ehci.txt

···
  - big-endian-desc : boolean, set this for hcds with big-endian descriptors
  - big-endian : boolean, for hcds with big-endian-regs + big-endian-desc
  - needs-reset-on-resume : boolean, set this to force EHCI reset after resume
+ - has-transaction-translator : boolean, set this if EHCI have a Transaction
+				Translator built into the root hub.
  - clocks : a list of phandle + clock specifier pairs
  - phys : phandle + phy specifier pair
  - phy-names : "usb"

drivers/usb/host/ehci-platform.c

···
 					  "needs-reset-on-resume"))
 			pdata->reset_on_resume = 1;
 
+		if (of_property_read_bool(dev->dev.of_node,
+					  "has-transaction-translator"))
+			pdata->has_tt = 1;
+
 		priv->num_phys = of_count_phandle_with_args(dev->dev.of_node,
 				"phys", "#phy-cells");
 		priv->num_phys = priv->num_phys > 0 ? priv->num_phys : 1;