Documentation: Update internal URL's

Update URL's to point to head rather than the deprecated
refs/heads/master.

Change-Id: I16f0c087762ff049115b67de3ac0b881aa4e4b40
Signed-off-by: Jon Murphy <[email protected]>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/79785
Tested-by: build bot (Jenkins) <[email protected]>
Reviewed-by: Matt DeVillier <[email protected]>

Author: jpmurphy-google

Documentation/mainboard/ocp/deltalake.md

@@ -222,4 +222,4 @@ and [u-root] as initramfs.
 [All about u-root]: https://github.com/linuxboot/book/tree/master/u-root
 [u-root]: https://u-root.org/
 [ChromeOS VPD]: https://chromium.googlesource.com/chromiumos/platform/vpd/+/master/README.md
-[src/mainboard/ocp/deltalake/vpd.h]: https://review.coreboot.org/plugins/gitiles/coreboot/+/refs/heads/master/src/mainboard/ocp/deltalake/vpd.h
+[src/mainboard/ocp/deltalake/vpd.h]: https://review.coreboot.org/plugins/gitiles/coreboot/+/HEAD/src/mainboard/ocp/deltalake/vpd.h

README.md

@@ -30,7 +30,7 @@ Code reviews are done in [the project's Gerrit
 instance](https://review.coreboot.org/).
 
 The code may be browsed via [coreboot's Gitiles
-instance](https://review.coreboot.org/plugins/gitiles/coreboot/+/refs/heads/master).
+instance](https://review.coreboot.org/plugins/gitiles/coreboot/+/HEAD).
 
 The coreboot project also maintains a
 [mirror](https://github.com/coreboot/coreboot) of the project on github.