udc: lpc32xx: make symbol 'lpc32xx_usbddata' static

udc: lpc32xx: make symbol 'lpc32xx_usbddata' static

The sparse tool complains as follows:

drivers/usb/gadget/udc/lpc32xx_udc.c:2989:25: warning:
 symbol 'lpc32xx_usbddata' was not declared. Should it be static?

This variable is not used outside of lpc32xx_udc.c, so this commit
marks it static.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20200707105350.7064-1-weiyongjun1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>