coreboot: Update to main branch

Update coreboot and the blobs directories to the main branch.
To avoid confusion.

BUG=b:294218930
TEST=CQ

Change-Id: I4dec10c6fd18dc557d65749c12d1891cf15bc6f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/5042214
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Tested-by: Jonathon Murphy <jpmurphy@google.com>
Commit-Queue: Jonathon Murphy <jpmurphy@google.com>
Auto-Submit: Jonathon Murphy <jpmurphy@google.com>
Reviewed-by: Mark Hasemeyer <markhas@google.com>
diff --git a/contrib/branch_tools/.fwcp_config_example b/contrib/branch_tools/.fwcp_config_example
index 37c8271..2b80ab2 100644
--- a/contrib/branch_tools/.fwcp_config_example
+++ b/contrib/branch_tools/.fwcp_config_example
@@ -25,9 +25,9 @@
 PROJ_F_BRANCH[default]="remotes/cros/main"
 PROJ_F_BRANCH[private_partner_overlay]="remotes/cros-internal/main"
 PROJ_F_BRANCH[private_chipset_overlay]="remotes/cros-internal/main"
-PROJ_F_BRANCH[coreboot]="remotes/cros/chromeos-2016.05"
-PROJ_F_BRANCH[coreboot_blobs]="remotes/cros/master"
-PROJ_F_BRANCH[amd_blobs]="remotes/cros/upstream/master"
+PROJ_F_BRANCH[coreboot]="remotes/cros/main"
+PROJ_F_BRANCH[coreboot_blobs]="remotes/cros/main"
+PROJ_F_BRANCH[amd_blobs]="remotes/cros/upstream/main"
 PROJ_F_BRANCH[vendor_firmware]="remotes/cros-internal/silverback"
 PROJ_F_BRANCH[u_boot]="remotes/cros/chromeos-v2020.10-rc1"
 PROJ_F_BRANCH[seabios]="remotes/cros/chromeos-2014.11.03"
diff --git a/contrib/branch_tools/cros_update_branch.readme.md b/contrib/branch_tools/cros_update_branch.readme.md
index 5dcb463..80be273 100644
--- a/contrib/branch_tools/cros_update_branch.readme.md
+++ b/contrib/branch_tools/cros_update_branch.readme.md
@@ -330,7 +330,7 @@
 PROJ_F_BRANCH[default]="remotes/cros/main"
 PROJ_F_BRANCH[private_partner_overlay]="remotes/cros-internal/main"
 PROJ_F_BRANCH[private_chipset_overlay]="remotes/cros-internal/main"
-PROJ_F_BRANCH[coreboot]="remotes/cros/chromeos-2016.05"
+PROJ_F_BRANCH[coreboot]="remotes/cros/main"
 ...
 ```