Add GUID for bootloader partition.
am: 151a24479c

Change-Id: I3cd799dabcd57c2dcad907549ef6c364c2c6e8d4

README

diff --git a/README b/README
index 32c56c4..a5d317b 100644
--- a/README
+++ b/README
@@ -92,6 +92,7 @@
               are the following special values:
 
                 brillo_boot
+                brillo_bootloader
                 brillo_system
                 brillo_odm
                 brillo_oem

bpttool

diff --git a/bpttool b/bpttool
index b479374..7b78e3d 100755
--- a/bpttool
+++ b/bpttool
@@ -69,6 +69,7 @@
 
 KNOWN_TYPE_GUIDS = {
     'brillo_boot': 'bb499290-b57e-49f6-bf41-190386693794',
+    'brillo_bootloader': '4892aeb3-a45f-4c5f-875f-da3303c0795c',
     'brillo_system': '0f2778c4-5cc1-4300-8670-6c88b7e57ed6',
     'brillo_odm': 'e99d84d7-2c1b-44cf-8c58-effae2dc2558',
     'brillo_oem': 'aa3434b2-ddc3-4065-8b1a-18e99ea15cb7',