build(imx8ulp): add build configs for imx8ulp

Add build configs for i.MX8ULP.

Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: I40ba84037a38034c596f78718d96d0f2551e1432
diff --git a/script/tf-coverity/tf-cov-make b/script/tf-coverity/tf-cov-make
index c048532..d9053bd 100755
--- a/script/tf-coverity/tf-cov-make
+++ b/script/tf-coverity/tf-cov-make
@@ -452,6 +452,8 @@
 make PLAT=imx8qm $(common_flags) all
 make PLAT=imx8qx $(common_flags) all
 
+make PLAT=imx8ulp $(common_flags) all
+
 make PLAT=imx93 $(common_flags) all
 
 # Platforms for NXP Layerscape