meta-facebook: yosemite4: Add check management board

Need to identify which management board for reusing common code.

Tested:
Run some common scripts to call function `check_nuvoton_board`.
Different management board will go different flow.

./usr/libexec/phosphor-state-manager/chassis-poweron
./usr/libexec/phosphor-state-manager/chassis-poweroff
./usr/libexec/phosphor-state-manager/chassis-powercycle

Signed-off-by: Tim Lee <timlee660101@gmail.com>
Change-Id: Ided1bfb2402e825300178daa7d9354962307c7e8
diff --git a/meta-facebook/meta-yosemite4/recipes-yosemite4/plat-tool/files/yosemite4-common-functions b/meta-facebook/meta-yosemite4/recipes-yosemite4/plat-tool/files/yosemite4-common-functions
index 0614ff0..4e948e6 100644
--- a/meta-facebook/meta-yosemite4/recipes-yosemite4/plat-tool/files/yosemite4-common-functions
+++ b/meta-facebook/meta-yosemite4/recipes-yosemite4/plat-tool/files/yosemite4-common-functions
@@ -20,3 +20,11 @@
     return 0
 }
 
+check_nuvoton_board()
+{
+    check_nuvoton=$(grep nuvoton /sys/firmware/devicetree/base/compatible)
+    if [ "$check_nuvoton" != "" ]; then
+        return 1
+    fi
+    return 0
+}