Export FrontendDvbtPlpMode

Test: make;
Change-Id: I3d4c0667ba1251b3038681759c50b453cd40a8ca
Merged-in: I3d4c0667ba1251b3038681759c50b453cd40a8ca
(cherry picked from commit e266073ed6747d0d2e85b0b623fceef29c004ad3)
diff --git a/tv/tuner/1.0/types.hal b/tv/tuner/1.0/types.hal
index 944da5a..8dce5d5 100644
--- a/tv/tuner/1.0/types.hal
+++ b/tv/tuner/1.0/types.hal
@@ -773,6 +773,7 @@
 /**
  *   Physical Layer Pipe (PLP) Mode for DVBT.
  */
+@export
 enum FrontendDvbtPlpMode : uint32_t {
     UNDEFINED,
     AUTO,