arch/arm/mach-imx/mach-mx53_ard.c: add missing iounmap

Add missing iounmap in error handling code, in a case where the function
already preforms iounmap on some other execution path.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression e;
statement S,S1;
int ret;
@@
e = \(ioremap\|ioremap_nocache\)(...)
... when != iounmap(e)
if (<+...e...+>) S
... when any
    when != iounmap(e)
*if (...)
   { ... when != iounmap(e)
     return ...; }
... when any
iounmap(e);
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-mx5/board-mx53_ard.c

@@ -189,8 +189,10 @@ static int weim_cs_config(void)
 		return -ENOMEM;
 
 	iomuxc_base = ioremap(MX53_IOMUXC_BASE_ADDR, SZ_4K);
-	if (!iomuxc_base)
+	if (!iomuxc_base) {
+		iounmap(weim_base);
 		return -ENOMEM;
+	}
 
 	/* CS1 timings for LAN9220 */
 	writel(0x20001, (weim_base + 0x18));