arch/arm64/imx9: Boot, move mmu init to correct place

MMU init must be after ddrinit.

Signed-off-by: Jouni Ukkonen <jouni.ukkonen@unikie.com>

arch/arm64/src/imx9/imx9_boot.c

@@ -124,10 +124,6 @@ void arm64_el_init(void)
 
 void arm64_chip_boot(void)
 {
-  /* MAP IO and DRAM, enable MMU. */
-
-  arm64_mmu_init(true);
-
 #ifdef CONFIG_IMX9_BOOTLOADER
   imx9_mix_powerup();
 
@@ -144,6 +140,10 @@ void arm64_chip_boot(void)
 #endif
 #endif
 
+  /* MAP IO and DRAM, enable MMU. */
+
+  arm64_mmu_init(true);
+
   /* Do UART early initialization & pin muxing */
 
 #ifdef CONFIG_IMX9_LPUART