imx: add i.MX8M into Kconfig

Add i.MX8M into Kconfig, create a new folder mx8m
dedicated for i.MX8M.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>
Reviewed-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/mach-imx/mx8m/Kconfig b/arch/arm/mach-imx/mx8m/Kconfig
new file mode 100644
index 0000000..3a84c2f
--- /dev/null
+++ b/arch/arm/mach-imx/mx8m/Kconfig
@@ -0,0 +1,10 @@
+if ARCH_MX8M
+
+config MX8M
+	bool
+	select ROM_UNIFIED_SECTIONS
+
+config SYS_SOC
+	default "mx8m"
+
+endif