usb: gadget: remove duplicated include from pxa25x_udc.c

From: Wei Yongjun <yongjun_wei@trendmicro.com.cn>

Remove duplicated include.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/pxa25x_udc.c

@@ -33,7 +33,6 @@
 #include <linux/dma-mapping.h>
 #include <linux/irq.h>
 #include <linux/clk.h>
-#include <linux/err.h>
 #include <linux/seq_file.h>
 #include <linux/debugfs.h>
 #include <linux/io.h>