Replaced MBEDTLS_GCM_LARGETABLE by MBEDTLS_GCM_LARGE_TABLE. Removed empty comment line in doc block.

Signed-off-by: Matthias Schulz <mschulz@hilscher.com>
diff --git a/include/mbedtls/gcm.h b/include/mbedtls/gcm.h
index 745cd28..98faa43 100644
--- a/include/mbedtls/gcm.h
+++ b/include/mbedtls/gcm.h
@@ -46,7 +46,7 @@
 
 #if !defined(MBEDTLS_GCM_ALT)
 
-#if defined(MBEDTLS_GCM_LARGETABLE)
+#if defined(MBEDTLS_GCM_LARGE_TABLE)
 #define MBEDTLS_GCM_HTABLE_SIZE 256
 #else
 #define MBEDTLS_GCM_HTABLE_SIZE 16