ALSA: line6: Move the contents of usbdefs.h into driver.h

Most of them are rather relevant with the definitions in driver.h,
and there are only a few lines, so just rip it off.

Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/usb/line6/midi.c

@@ -17,7 +17,6 @@
 
 #include "driver.h"
 #include "midi.h"
-#include "usbdefs.h"
 
 #define line6_rawmidi_substream_midi(substream) \
 	((struct snd_line6_midi *)((substream)->rmidi->private_data))