prjxray/segmaker.py: add GTX support

Signed-off-by: Hans Baier <foss@hans-baier.de>
diff --git a/prjxray/segmaker.py b/prjxray/segmaker.py
index 6689d6f..7bafec7 100644
--- a/prjxray/segmaker.py
+++ b/prjxray/segmaker.py
@@ -391,6 +391,12 @@
                 tile_type_norm = 'GTP_COMMON'
             if 'GTP_INT_INTERFACE' in tile_type_norm:
                 tile_type_norm = 'GTP_INT_INTERFACE'
+            if 'GTX_CHANNEL' in tile_type_norm:
+                tile_type_norm = 'GTX_CHANNEL'
+            if 'GTX_COMMON' in tile_type_norm:
+                tile_type_norm = 'GTX_COMMON'
+            if 'GTX_INT_INTERFACE' in tile_type_norm:
+                tile_type_norm = 'GTX_INT_INTERFACE'
 
             if tile_type_norm in ['LIOI', 'RIOI']:
                 tile_type_norm = 'IOI'