meta-google: Depend on tpm-layer for libhoth

You can't build meta-google without including libhoth support.

Change-Id: I77799f63c444bcbd1ce7dd3761fccf29a60d3cd4
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/meta-google/conf/layer.conf b/meta-google/conf/layer.conf
index a75bd8b..f4568aa 100644
--- a/meta-google/conf/layer.conf
+++ b/meta-google/conf/layer.conf
@@ -15,4 +15,4 @@
 BBFILE_PATTERN_google-layer := "^${LAYERDIR}/"
 LAYERVERSION_google-layer = "1"
 LAYERSERIES_COMPAT_google-layer = "langdale mickledore"
-LAYERDEPENDS_google-layer += "core phosphor-layer"
+LAYERDEPENDS_google-layer += "core phosphor-layer tpm-layer"