imx8ulp: build ahab

The ahab was missed to be compiled, so add it back.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/mach-imx/imx8ulp/Kconfig b/arch/arm/mach-imx/imx8ulp/Kconfig
index c1c1aa0..49ea252 100644
--- a/arch/arm/mach-imx/imx8ulp/Kconfig
+++ b/arch/arm/mach-imx/imx8ulp/Kconfig
@@ -1,5 +1,10 @@
 if ARCH_IMX8ULP
 
+config AHAB_BOOT
+	bool "Support i.MX8ULP AHAB features"
+	help
+	  This option enables the support for AHAB secure boot.
+
 config IMX8ULP
 	bool