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/lowlevel_init.S b/arch/arm/mach-imx/mx8m/lowlevel_init.S
new file mode 100644
index 0000000..d388f3b
--- /dev/null
+++ b/arch/arm/mach-imx/mx8m/lowlevel_init.S
@@ -0,0 +1,63 @@
+/*
+ * Copyright 2017 NXP
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <config.h>
+
+.align 8
+.global rom_pointer
+rom_pointer:
+	.space 256
+
+/*
+ * Routine: save_boot_params (called after reset from start.S)
+ */
+
+.global save_boot_params
+save_boot_params:
+	/* The firmware provided ATAG/FDT address can be found in r2/x0 */
+	adr	x0, rom_pointer
+	stp	x1, x2, [x0], #16
+	stp	x3, x4, [x0], #16
+	stp	x5, x6, [x0], #16
+	stp	x7, x8, [x0], #16
+	stp	x9, x10, [x0], #16
+	stp	x11, x12, [x0], #16
+	stp	x13, x14, [x0], #16
+	stp	x15, x16, [x0], #16
+	stp	x17, x18, [x0], #16
+	stp	x19, x20, [x0], #16
+	stp	x21, x22, [x0], #16
+	stp	x23, x24, [x0], #16
+	stp	x25, x26, [x0], #16
+	stp	x27, x28, [x0], #16
+	stp	x29, x30, [x0], #16
+	mov	x30, sp
+	str	x30, [x0], #8
+
+	/* Returns */
+	b	save_boot_params_ret
+
+.global restore_boot_params
+restore_boot_params:
+	adr	x0, rom_pointer
+	ldp	x1, x2, [x0], #16
+	ldp	x3, x4, [x0], #16
+	ldp	x5, x6, [x0], #16
+	ldp	x7, x8, [x0], #16
+	ldp	x9, x10, [x0], #16
+	ldp	x11, x12, [x0], #16
+	ldp	x13, x14, [x0], #16
+	ldp	x15, x16, [x0], #16
+	ldp	x17, x18, [x0], #16
+	ldp	x19, x20, [x0], #16
+	ldp	x21, x22, [x0], #16
+	ldp	x23, x24, [x0], #16
+	ldp	x25, x26, [x0], #16
+	ldp	x27, x28, [x0], #16
+	ldp	x29, x30, [x0], #16
+	ldr	x0, [x0]
+	mov	sp, x0
+	ret