imx: add basic i.MX9 support

Add i.MX9 Kconfig and basic files for the new SoC

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/mach-imx/imx9/Makefile b/arch/arm/mach-imx/imx9/Makefile
new file mode 100644
index 0000000..773b12e
--- /dev/null
+++ b/arch/arm/mach-imx/imx9/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright 2022 NXP
+
+obj-y += lowlevel_init.o
+obj-y += soc.o clock.o