Disable LAVA test for failed NXP images

NXP configs have known issue and keep blocking CI.
Disable for the time being until the issue got fixed.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: I1333f3ea3d30f44780b38447eb3789d94fe2bb28
diff --git a/lava_helper/lava_helper_configs.py b/lava_helper/lava_helper_configs.py
index 3242f3d..e8996a5 100644
--- a/lava_helper/lava_helper_configs.py
+++ b/lava_helper/lava_helper_configs.py
@@ -302,7 +302,6 @@
     "qemu_mps2_bl2": qemu_mps2_bl2,
     "musca_b1": musca_b1_bl2,
     "stm32l562e_dk": stm32l562e_dk,
-    "lpcxpresso55s69": lpcxpresso55s69,
     "psoc64": psoc64,
 }