Fix additional misspellings found by codespell

Remaining hits seem to be hex data, certificates,
and other miscellaneous exceptions.
List generated by running codespell -w -L 
keypair,Keypair,KeyPair,keyPair,ciph,nd

Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/tests/suites/test_suite_ecdh.function b/tests/suites/test_suite_ecdh.function
index 6893bcf..68db8fe 100644
--- a/tests/suites/test_suite_ecdh.function
+++ b/tests/suites/test_suite_ecdh.function
@@ -262,7 +262,7 @@
     rnd_info_B.buf = dB->x;
     rnd_info_B.length = dB->len;
 
-    /* The ECDH context is not guaranteed ot have an mbedtls_ecp_group structure
+    /* The ECDH context is not guaranteed to have an mbedtls_ecp_group structure
      * in every configuration, therefore we load it separately. */
     TEST_ASSERT( mbedtls_ecp_group_load( &grp, id ) == 0 );