ARM: mxc: fix Kconfig typo 'i.MX51'

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

arch/arm/plat-mxc/Kconfig

@@ -39,7 +39,7 @@ config ARCH_MX503
 	select ARCH_MX50_SUPPORTED
 	select ARCH_MX53_SUPPORTED
 	help
-	  This enables support for machines using Freescale's i.MX50 and i.MX51
+	  This enables support for machines using Freescale's i.MX50 and i.MX53
 	  processors.
 
 config ARCH_MX51