[ARM] 2944/1: GCC 4 mx1ads serial driver compile fix

Patch from Vincent Sanders

When building the mx1ads ARM platforms the serial driver fails to compile
with GCC 4.01 due to extern/static ambiguity.

Signed-off-by: Vincent Sanders <vince@arm.linux.org.uk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/serial/imx.c b/drivers/serial/imx.c
index 4c985e6..4e1e80a 100644
--- a/drivers/serial/imx.c
+++ b/drivers/serial/imx.c
@@ -860,7 +860,7 @@
 	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
 }
 
-extern struct uart_driver imx_reg;
+static struct uart_driver imx_reg;
 static struct console imx_console = {
 	.name		= "ttySMX",
 	.write		= imx_console_write,