Fix typos

Signed-off-by: Tom Cosgrove <tom.cosgrove@arm.com>
diff --git a/scripts/mbedtls_dev/bignum_common.py b/scripts/mbedtls_dev/bignum_common.py
index dd4fc36..c4efabf 100644
--- a/scripts/mbedtls_dev/bignum_common.py
+++ b/scripts/mbedtls_dev/bignum_common.py
@@ -249,7 +249,7 @@
     #pylint: disable=abstract-method
     """Target for bignum mod_raw test case generation."""
     moduli = MODULI_DEFAULT # type: List[str]
-    mongtomgery_form_a = False
+    montgomery_form_a = False
     disallow_zero_a = False
 
     def __init__(self, val_n: str, val_a: str, val_b: str = "0",
@@ -272,7 +272,7 @@
 
     @property
     def arg_a(self) -> str:
-        if self.mongtomgery_form_a:
+        if self.montgomery_form_a:
             value_a = self.to_montgomery(self.int_a)
         else:
             value_a = self.int_a
diff --git a/scripts/mbedtls_dev/bignum_core.py b/scripts/mbedtls_dev/bignum_core.py
index 3bd7f11..24d37cb 100644
--- a/scripts/mbedtls_dev/bignum_core.py
+++ b/scripts/mbedtls_dev/bignum_core.py
@@ -757,7 +757,7 @@
     test_function = "mpi_core_exp_mod"
     test_name = "Core modular exponentiation (Mongtomery form only)"
     input_style = "fixed"
-    mongtomgery_form_a = True
+    montgomery_form_a = True
 
     def result(self) -> List[str]:
         # Result has to be given in Montgomery form too
diff --git a/scripts/mbedtls_dev/bignum_mod.py b/scripts/mbedtls_dev/bignum_mod.py
index 6428873..25afe30 100644
--- a/scripts/mbedtls_dev/bignum_mod.py
+++ b/scripts/mbedtls_dev/bignum_mod.py
@@ -76,7 +76,7 @@
     arity = 1
     suffix = True
     disallow_zero_a = True
-    mongtomgery_form_a = True
+    montgomery_form_a = True
 
     def result(self) -> List[str]:
         result = bignum_common.invmod_positive(self.int_a, self.int_n)
diff --git a/scripts/mbedtls_dev/bignum_mod_raw.py b/scripts/mbedtls_dev/bignum_mod_raw.py
index 461b1f2..ae855e8 100644
--- a/scripts/mbedtls_dev/bignum_mod_raw.py
+++ b/scripts/mbedtls_dev/bignum_mod_raw.py
@@ -64,7 +64,7 @@
     input_style = "arch_split"
     arity = 1
     suffix = True
-    mongtomgery_form_a = True
+    montgomery_form_a = True
     disallow_zero_a = True
 
     def result(self) -> List[str]: