usb: gadget: add 'quirk_altset_not_supp' to usb_gadget

Due to some UDC controllers may not support altsettings, usb gadget layer
needs to provide a generic way to inform gadget functions about non-standard
hardware limitations.

This patch adds 'quirk_altset_not_supp' field to struct usb_gadget and helper
function gadget_is_altset_supported(). It also sets 'quirk_altset_not_supp'
to 1 in pxa25x_udc and pxa27x_udc drivers, which have such limitation.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index cea0511..31be84b 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -572,6 +572,7 @@
 	unsigned			a_hnp_support:1;
 	unsigned			a_alt_hnp_support:1;
 	unsigned			quirk_ep_out_aligned_size:1;
+	unsigned			quirk_altset_not_supp:1;
 	unsigned			is_selfpowered:1;
 	unsigned			deactivated:1;
 	unsigned			connected:1;
@@ -610,6 +611,16 @@
 }
 
 /**
+ * gadget_is_altset_supported - return true iff the hardware supports
+ *	altsettings
+ * @g: controller to check for quirk
+ */
+static inline int gadget_is_altset_supported(struct usb_gadget *g)
+{
+	return !g->quirk_altset_not_supp;
+}
+
+/**
  * gadget_is_dualspeed - return true iff the hardware handles high speed
  * @g: controller that might support both high and full speeds
  */