HID: picolcd: fix build failure

Using copy_{to,from}_user requires the include of linux/uaccess.h.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-picolcd.c

@@ -35,6 +35,7 @@
 #include <linux/debugfs.h>
 
 #include <linux/completion.h>
+#include <linux/uaccess.h>
 
 #define PICOLCD_NAME "PicoLCD (graphic)"