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/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 2213729..6b3ba48 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -2387,7 +2387,7 @@
  *                 ones going through the authentication-decryption phase.
  *
  * \note           This is a security trade-off related to the fact that it's
- *                 often relatively easy for an active attacker ot inject UDP
+ *                 often relatively easy for an active attacker to inject UDP
  *                 datagrams. On one hand, setting a low limit here makes it
  *                 easier for such an attacker to forcibly terminated a
  *                 connection. On the other hand, a high limit or no limit