mx7ulp: soc: s_init should only be executed once

On SPL enabled systems, the current s_init code (wdog, clock and ldo
init) is executed twice (by SPL and u-boot). This is not necessary and
might lead to boot issues (ie, starting PMC1 when it is already running).

Signed-off-by: Jorge Ramirez-Ortiz <jorge@foundries.io>
Reviewed-by: Fabio Estevam <festevam@gmail.com>

arch/arm/mach-imx/mx7ulp/soc.c

@@ -117,6 +117,7 @@ void init_wdog(void)
 	disable_wdog(WDG2_RBASE);
 }
 
+#if !defined(CONFIG_SPL) || (defined(CONFIG_SPL) && defined(CONFIG_SPL_BUILD))
 #if defined(CONFIG_LDO_ENABLED_MODE)
 static void init_ldo_mode(void)
 {
@@ -174,6 +175,7 @@ void s_init(void)
 #endif
 	return;
 }
+#endif
 
 #ifndef CONFIG_ULP_WATCHDOG
 void reset_cpu(ulong addr)