The is_valid() function is needed to not filter out test cases

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/scripts/mbedtls_dev/ecp.py b/scripts/mbedtls_dev/ecp.py
index 556209f..354b234 100644
--- a/scripts/mbedtls_dev/ecp.py
+++ b/scripts/mbedtls_dev/ecp.py
@@ -74,6 +74,10 @@
         result = self.int_a % self.int_n
         return [self.format_result(result)]
 
+    @property
+    def is_valid(self) -> bool:
+        return True
+
 
 class EcpP224R1Raw(bignum_common.ModOperationCommon,
                    EcpTarget):
@@ -136,6 +140,10 @@
         result = self.int_a % self.int_n
         return [self.format_result(result)]
 
+    @property
+    def is_valid(self) -> bool:
+        return True
+
 
 class EcpP521R1Raw(bignum_common.ModOperationCommon,
                    EcpTarget):
@@ -223,3 +231,7 @@
     def result(self) -> List[str]:
         result = self.int_a % self.int_n
         return [self.format_result(result)]
+
+    @property
+    def is_valid(self) -> bool:
+        return True