Add LMS implementation

Also an LM-OTS implementation as one is required for LMS.

Signed-off-by: Raef Coles <raef.coles@arm.com>
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index 6b330a7..37253ab 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -353,6 +353,16 @@
 #error "MBEDTLS_MD_C defined, but not all prerequisites"
 #endif
 
+#if defined(MBEDTLS_LMOTS_C) &&                                       \
+    ( !defined(MBEDTLS_MD_C) )
+#error "MBEDTLS_LMOTS_C requires MBEDTLS_MD_C"
+#endif
+
+#if defined(MBEDTLS_LMS_C) &&                                          \
+    ( !defined(MBEDTLS_LMOTS_C) || !defined(MBEDTLS_MD_C) )
+#error "MBEDTLS_LMS_C requires MBEDTLS_LMOTS_C and MBEDTLS_MD_C"
+#endif
+
 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C) &&                          \
     ( !defined(MBEDTLS_PLATFORM_C) || !defined(MBEDTLS_PLATFORM_MEMORY) )
 #error "MBEDTLS_MEMORY_BUFFER_ALLOC_C defined, but not all prerequisites"