gpio: atmel: add copyright and remove error header info

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Jens Scharsig <js_at_ng@scharsoft.de>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/drivers/gpio/at91_gpio.c b/drivers/gpio/at91_gpio.c
index 6073843..af09786 100644
--- a/drivers/gpio/at91_gpio.c
+++ b/drivers/gpio/at91_gpio.c
@@ -1,5 +1,5 @@
 /*
- * Memory Setup stuff - taken from blob memsetup.S
+ * Copyright (C) 2013 Bo Shen <voice.shen@atmel.com>
  *
  * Copyright (C) 2009 Jens Scharsig (js_at_ng@scharsoft.de)
  *