Add Witherspoon GPIO JSON

These GPIOs are used by the code in the skeleton repo.

Resolves openbmc/openbmc#3332

Change-Id: If2b320bbd1ed29d888bdf2dc9168489d898407aa
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/meta-witherspoon/recipes-phosphor/skeleton/obmc-libobmc-intf.bbappend b/meta-witherspoon/recipes-phosphor/skeleton/obmc-libobmc-intf.bbappend
new file mode 100644
index 0000000..72d991c
--- /dev/null
+++ b/meta-witherspoon/recipes-phosphor/skeleton/obmc-libobmc-intf.bbappend
@@ -0,0 +1 @@
+FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"