openpower/configs: Set default hostname to skiroot

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
diff --git a/openpower/configs/openpower_mambo_defconfig b/openpower/configs/openpower_mambo_defconfig
index a958ce3..c7ba28e 100644
--- a/openpower/configs/openpower_mambo_defconfig
+++ b/openpower/configs/openpower_mambo_defconfig
@@ -18,6 +18,8 @@
 # we don't need a PNOR layout for Mambo
 BR2_PACKAGE_OPENPOWER_PNOR=n
 
+BR2_TARGET_GENERIC_HOSTNAME="skiroot"
+
 # skiboot will be built but we don't need embedded payload
 BR2_PACKAGE_SKIBOOT=y
 BR2_PACKAGE_SKIBOOT_EMBED_PAYLOAD=n