board: fsl: lx2160a: free up arch_misc_init

Currently LX2 board code uses arch_misc_init to set up the board mux on
RDB and QDS.  Move this code to misc_init_r.  This is consistent with LS
gen 2 and T series SoCs/boards.

Signed-off-by: Alex Marginean <alexandru.marginean@nxp.com>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/configs/lx2160ardb_tfa_SECURE_BOOT_defconfig b/configs/lx2160ardb_tfa_SECURE_BOOT_defconfig
index 01a356f..92020cb 100644
--- a/configs/lx2160ardb_tfa_SECURE_BOOT_defconfig
+++ b/configs/lx2160ardb_tfa_SECURE_BOOT_defconfig
@@ -18,6 +18,7 @@
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="console=ttyAMA0,115200 root=/dev/ram0 earlycon=pl011,mmio32,0x21c0000 ramdisk_size=0x2000000 default_hugepagesz=1024m hugepagesz=1024m hugepages=2 pci=pcie_bus_perf"
 # CONFIG_USE_BOOTCOMMAND is not set
+CONFIG_MISC_INIT_R=y
 CONFIG_CMD_GREPENV=y
 CONFIG_CMD_EEPROM=y
 CONFIG_CMD_GPT=y