meta-google: Remove libhoth recipe

Use the libhoth recipe in meta-security instead of openbmc one. Set the
source rev override until that bump is submitted and subtree updated.

libhoth source bump in
- https://lore.kernel.org/yocto/20230517172730.3837643-1-jebr@google.com/T/#u

Change-Id: I6099d6351417dcef9eb3b4d297de43a5e229d7dd
Signed-off-by: Willy Tu <wltu@google.com>
diff --git a/meta-google/recipes-tpm/hoth/libhoth_%.bbappend b/meta-google/recipes-tpm/hoth/libhoth_%.bbappend
new file mode 100644
index 0000000..8d57437
--- /dev/null
+++ b/meta-google/recipes-tpm/hoth/libhoth_%.bbappend
@@ -0,0 +1 @@
+SRCREV:gbmc = "769296220dc88df33f4726aa11e39e049257b3c4"