pxa27x_udc: remove call to unimplemented set_GPIO_mode()

If CONFIG_USB_DEV_PULLUP_GPIO is defined, a link error occurs because the
set_GPIO_mode() helper function is not implemented.  This function doesn't do
much except make the code a little more readable, so I just manually coded its
equivalent and removed the prototype from the header file.  It is invoked no
where else in the code.

While I was at it, I noticed that two other function prototypes in the same
header file are also neither implemented nor invoked anywhere, so I removed them
as well.

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
diff --git a/drivers/usb/gadget/pxa27x_udc.c b/drivers/usb/gadget/pxa27x_udc.c
index 4c00081..71cc0f2 100644
--- a/drivers/usb/gadget/pxa27x_udc.c
+++ b/drivers/usb/gadget/pxa27x_udc.c
@@ -610,7 +610,9 @@
 
 #ifdef CONFIG_USB_DEV_PULLUP_GPIO
 	/* Turn on the USB connection by enabling the pullup resistor */
-	set_GPIO_mode(CONFIG_USB_DEV_PULLUP_GPIO | GPIO_OUT);
+	writel(readl(GPDR(CONFIG_USB_DEV_PULLUP_GPIO))
+		     | GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO),
+	       GPDR(CONFIG_USB_DEV_PULLUP_GPIO));
 	writel(GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO), GPSR(CONFIG_USB_DEV_PULLUP_GPIO));
 #else
 	/* Host port 2 transceiver D+ pull up enable */