usb: gadget: ci13xx_udc.c: fix compile warning

Fix the following compile warning:

| usb/gadget/ci13xxx_udc.c: In function 'show_registers':
| usb/gadget/ci13xxx_udc.c:1242:1: warning: the frame size of 2064 bytes is larger than 1024 bytes

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>