Remove `MBEDTLS_KEY_EXCHANGE_RSA_ENABLED` config option

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index c2b5200..4328f71 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -87,12 +87,6 @@
 #error "MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED defined, but not all prerequisites"
 #endif
 
-#if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) &&                       \
-    ( !defined(MBEDTLS_RSA_C) || !defined(MBEDTLS_X509_CRT_PARSE_C) || \
-      !defined(MBEDTLS_PKCS1_V15) )
-#error "MBEDTLS_KEY_EXCHANGE_RSA_ENABLED defined, but not all prerequisites"
-#endif
-
 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED) &&    \
     ( !defined(PSA_WANT_ALG_JPAKE) ||                   \
       !defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR_BASIC) || \
@@ -155,8 +149,7 @@
 #endif
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) &&                                    \
-    !(defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED) ||                          \
-      defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                    \
+    !(defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                    \
       defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED) ||                  \
       defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) ||                     \
       defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED) ||                   \