Drop broadcom repo

No longer used.

BUG=b:139435424
TEST=none

Cq-Depend: chromium:1956106
Change-Id: I2f1cde37401b0cf5cf602a3a076ef8c0182d2fcf
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/manifest/+/1956127Tested-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Mike Nichols <mikenichols@chromium.org>
Commit-Queue: Brian Norris <briannorris@chromium.org>

full.xml

@@ -230,8 +230,6 @@ Your sources have been sync'd successfully.
   <project path="src/third_party/breakpad/src/third_party/lss"
            name="linux-syscall-support"
            revision="8048ece6c16c91acfe0d36d1d3cc0890ab6e945c" />
-  <project path="src/third_party/broadcom"
-           name="chromiumos/third_party/broadcom" />
   <project path="src/third_party/cbootimage"
            groups="firmware"
            name="chromiumos/third_party/cbootimage" />