Fix incorrect array length in function prototype

Issue #9179 (MBEDTLS_SSL_CID_OUT_LEN_MAX changed to
MBEDTLS_SSL_CID_IN_LEN_MAX in library\ssl.h and library\ssl_tls.c)

Signed-off-by: Sam Berry <sam.berry@arm.com>
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index c2c2b6f..e2f583f 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -132,7 +132,7 @@
 
 int mbedtls_ssl_get_own_cid(mbedtls_ssl_context *ssl,
                             int *enabled,
-                            unsigned char own_cid[MBEDTLS_SSL_CID_OUT_LEN_MAX],
+                            unsigned char own_cid[MBEDTLS_SSL_CID_IN_LEN_MAX],
                             size_t *own_cid_len)
 {
     *enabled = MBEDTLS_SSL_CID_DISABLED;