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: NFabio Estevam <fabio.estevam@freescale.com>

arch/arm/cpu/arm1136/mx35/generic.c

@@ -422,6 +422,7 @@ U_BOOT_CMD(
 	""
 );
 
+#if defined(CONFIG_DISPLAY_CPUINFO)
 static char *get_reset_cause(void)
 {
 	/* read RCSR register from CCM module */
@@ -444,7 +445,6 @@ static char *get_reset_cause(void)
 	}
 }
 
-#if defined(CONFIG_DISPLAY_CPUINFO)
 int print_cpuinfo(void)
 {
 	u32 srev = get_cpu_rev();