imx: mx8m: add soc related settings and files

Add SoC level initialization code
 - arch_cpu_init
 - mmu table
 - detect cpu revision
 - reset cpu and wdog settings
 - timer init
 - wdog settings
 - lowlevel init to save/restore registers
 - a few dummy header file to avoid build failure
 - ft_system_setup

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
diff --git a/arch/arm/mach-imx/mx8m/Makefile b/arch/arm/mach-imx/mx8m/Makefile
index 05f3884..b1c5d74 100644
--- a/arch/arm/mach-imx/mx8m/Makefile
+++ b/arch/arm/mach-imx/mx8m/Makefile
@@ -4,4 +4,5 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-y += clock.o clock_slice.o
+obj-y += lowlevel_init.o
+obj-y += clock.o clock_slice.o soc.o