usb: dwc3: fix few coding style problems

There were a few coding style issues with this driver
which are now fixed:

drivers/usb/dwc3/debugfs.c:48: WARNING: Use #include \
	<linux/uaccess.h> instead of <asm/uaccess.h>
drivers/usb/dwc3/debugfs.c:484: ERROR: space required \
	before the open brace '{'
drivers/usb/dwc3/ep0.c:261: WARNING: line over 80 characters
drivers/usb/dwc3/ep0.c:287: WARNING: suspect code indent \
	for conditional statements (16, 23)
drivers/usb/dwc3/gadget.c:749: WARNING: line over 80 characters
drivers/usb/dwc3/gadget.c:1267: WARNING: line over 80 characters
drivers/usb/dwc3/gadget.h:116: WARNING: line over 80 characters
drivers/usb/dwc3/io.h:42: WARNING: Use #include \
	<linux/io.h> instead of <asm/io.h>

Signed-off-by: Felipe Balbi <balbi@ti.com>