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/Makefile b/arch/arm/mach-imx/Makefile
index e38b560..4c4e15c 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -132,4 +132,4 @@
 obj-$(CONFIG_MX6) += mx6/
 obj-$(CONFIG_MX7) += mx7/
 obj-$(CONFIG_ARCH_MX7ULP) += mx7ulp/
-
+obj-$(CONFIG_MX8M) += mx8m/