usb: chipidea: add support for roles

Add some generic code for roles and implement simple role switching
based on ID pin state and/or a sysfs file. At this, we also rename
the device to ci_hdrc, which is what it is.

The "manual" switch is made into a sysfs file and not debugfs, because
it might be useful even in non-debug context. For some boards, like
sheevaplug, it seems to be the only way to switch roles without modifying
the hardware, since the ID pin is always grounded.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/chipidea/ci13xxx_pci.c

@@ -69,9 +69,9 @@ static int __devinit ci13xxx_pci_probe(struct pci_dev *pdev,
 	pci_set_master(pdev);
 	pci_try_set_mwi(pdev);
 
-	plat_ci = platform_device_alloc("ci_udc", -1);
+	plat_ci = platform_device_alloc("ci_hdrc", -1);
 	if (!plat_ci) {
-		dev_err(&pdev->dev, "can't allocate ci_udc platform device\n");
+		dev_err(&pdev->dev, "can't allocate ci_hdrc platform device\n");
 		retval = -ENOMEM;
 		goto disable_device;
 	}