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/Kconfig b/arch/arm/mach-imx/Kconfig
index 6b59752..b72b6af 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -166,7 +166,7 @@
 
 config IMX8_ROMAPI
 	def_bool y
-	depends on IMX8MN || IMX8MP || IMX8ULP
+	depends on IMX8MN || IMX8MP || IMX8ULP || IMX9
 
 config SPL_IMX_ROMAPI_LOADADDR
 	hex "Default load address to load image through ROM API"