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>
diff --git a/drivers/hid/hid-picolcd.c b/drivers/hid/hid-picolcd.c
index 66f9cfd..0eacc6b 100644
--- a/drivers/hid/hid-picolcd.c
+++ b/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)"