Build: Disable FP related configs on CS300

There is a known issue in TF-M related to FP build on CS300. Disable
these configs to unblock CI nightly job.

This patch should be reverted once the issue got fixed.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: I7d613947b0b66a78b2d705230c14ba868e2ed750
diff --git a/build_helper/build_helper_configs.py b/build_helper/build_helper_configs.py
index 01c6904..a9abdf5 100755
--- a/build_helper/build_helper_configs.py
+++ b/build_helper/build_helper_configs.py
@@ -441,9 +441,7 @@
                 }
 
 config_fp = {"seed_params": {
-                "tfm_platform":     ["arm/mps2/an521",
-                                     "arm/mps3/corstone300/an552",
-                                     "arm/mps3/corstone300/fvp"],
+                "tfm_platform":     ["arm/mps2/an521"],
                 "compiler":         ["GCC_10_3"],
                 "isolation_level":  ["1", "2"],
                 "test_regression":  ["RegBL2, RegS, RegNS"],