keymaster.proto: Add boot_hash to SetBootStateRequest.

Change-Id: I398e700f754074de4c10a862501fd9c1f82ff3ef
diff --git a/nugget/proto/nugget/app/keymaster/keymaster.proto b/nugget/proto/nugget/app/keymaster/keymaster.proto
index 99a18ef..fd35c4b 100644
--- a/nugget/proto/nugget/app/keymaster/keymaster.proto
+++ b/nugget/proto/nugget/app/keymaster/keymaster.proto
@@ -310,6 +310,7 @@
   uint32 color = 3;
   uint32 system_version = 4;
   uint32 system_security_level = 5;
+  bytes boot_hash = 6;               // This is a SHA256 digest.
 }
 message SetBootStateResponse {
   // Specified in keymaster_defs.proto:ErrorCode