usb: musb: add debugfs support

for now only a simple register dump entry (which can
be rather useful on debugging) and a way to start
test modes.

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/musb/Makefile b/drivers/usb/musb/Makefile
index db7933d..a1677f9 100644
--- a/drivers/usb/musb/Makefile
+++ b/drivers/usb/musb/Makefile
@@ -42,6 +42,10 @@
 	musb_hdrc-objs		+= musb_virthub.o musb_host.o
 endif
 
+ifeq ($(CONFIG_DEBUG_FS),y)
+	musb_hdrc-objs		+= musb_debugfs.o
+endif
+
 # the kconfig must guarantee that only one of the
 # possible I/O schemes will be enabled at a time ...
 # PIO only, or DMA (several potential schemes).