Add i.MXRT1020 support

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
diff --git a/arch/arm/mach-imx/imxrt/Kconfig b/arch/arm/mach-imx/imxrt/Kconfig
index e3aff11..f28d52d 100644
--- a/arch/arm/mach-imx/imxrt/Kconfig
+++ b/arch/arm/mach-imx/imxrt/Kconfig
@@ -3,6 +3,10 @@
 config IMXRT
 	bool
 
+config IMXRT1020
+	bool
+	select IMXRT
+
 config IMXRT1050
 	bool
 	select IMXRT