mx35: generic: Let get_reset_cause be defined only when CONFIG_DISPLAY_CPUINFO is selected

get_reset_cause() function is only used inside print_cpuinfo(), so let it be
defined only when CONFIG_DISPLAY_CPUINFO is selected.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/arch/arm/cpu/arm1136/mx35/generic.c b/arch/arm/cpu/arm1136/mx35/generic.c
index d41613e..986b1f9 100644
--- a/arch/arm/cpu/arm1136/mx35/generic.c
+++ b/arch/arm/cpu/arm1136/mx35/generic.c
@@ -422,6 +422,7 @@
 	""
 );
 
+#if defined(CONFIG_DISPLAY_CPUINFO)
 static char *get_reset_cause(void)
 {
 	/* read RCSR register from CCM module */
@@ -444,7 +445,6 @@
 	}
 }
 
-#if defined(CONFIG_DISPLAY_CPUINFO)
 int print_cpuinfo(void)
 {
 	u32 srev = get_cpu_rev();