imx: add Kconfig entry for i.MX8QXP

Add Kconfig entry for i.MX8QXP

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Anatolij Gustschin <agust@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/mach-imx/imx8/Kconfig b/arch/arm/mach-imx/imx8/Kconfig
new file mode 100644
index 0000000..28910c1
--- /dev/null
+++ b/arch/arm/mach-imx/imx8/Kconfig
@@ -0,0 +1,13 @@
+if ARCH_IMX8
+
+config IMX8
+	bool
+
+config IMX8QXP
+	select IMX8
+	bool
+
+config SYS_SOC
+	default "imx8"
+
+endif