drm_hwcomposer: Add DrmConnector::name function

Connectors usually are referred by names, but libdrm stores type and
id only as a numbers so for more convenience conversion function from
integerst to string should be added.

Signed-off-by: Roman Kovalivskyi <roman.kovalivskyi@globallogic.com>
diff --git a/include/drmconnector.h b/include/drmconnector.h
index 9c526c8..c9fd7ab 100644
--- a/include/drmconnector.h
+++ b/include/drmconnector.h
@@ -23,6 +23,7 @@
 
 #include <stdint.h>
 #include <xf86drmMode.h>
+#include <string>
 #include <vector>
 
 namespace android {
@@ -49,6 +50,8 @@
   bool writeback() const;
   bool valid_type() const;
 
+  std::string name() const;
+
   int UpdateModes();
 
   const std::vector<DrmMode> &modes() const {
@@ -86,6 +89,7 @@
   int display_;
 
   uint32_t type_;
+  uint32_t type_id_;
   drmModeConnection state_;
 
   uint32_t mm_width_;