poky: reset subtree on master HEAD(a88251b3e7)

As part of the last subtree update, I used master-next as the
subtree basis because there was a fix we needed in order to get QEMU
to pass.  I didn't realize that master-next deviated (because they use
to just have short-term patches in it).  Reset the content to the same
fix but from the master branch.

Change-Id: Ic7d2f0ac42e9da3eb263586b26ba56d8798d5bcf
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
diff --git a/poky/meta/conf/layer.conf b/poky/meta/conf/layer.conf
index efbf261..f2bca0a 100644
--- a/poky/meta/conf/layer.conf
+++ b/poky/meta/conf/layer.conf
@@ -7,12 +7,12 @@
 BBFILE_PATTERN_core = "^${LAYERDIR}/"
 BBFILE_PRIORITY_core = "5"
 
-LAYERSERIES_CORENAMES = "scarthgap"
+LAYERSERIES_CORENAMES = "scarthgap styhead"
 
 # This should only be incremented on significant changes that will
 # cause compatibility issues with other layers
 LAYERVERSION_core = "15"
-LAYERSERIES_COMPAT_core = "scarthgap"
+LAYERSERIES_COMPAT_core = "styhead"
 
 BBLAYERS_LAYERINDEX_NAME_core = "openembedded-core"