meta-aspeed: ast2600: Sign the SPL with socsec by default

Signing the SPL when secure-boot is disabled has no impact, the SoC will
continue to bootstrap as normal.

Change-Id: I05c1db80cb4bec44ca315190f5b3c1d97168d1d5
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
diff --git a/meta-aspeed/conf/machine/include/ast2600.inc b/meta-aspeed/conf/machine/include/ast2600.inc
index fff5465..1e5e1f8 100644
--- a/meta-aspeed/conf/machine/include/ast2600.inc
+++ b/meta-aspeed/conf/machine/include/ast2600.inc
@@ -1,4 +1,9 @@
 SOC_FAMILY = "aspeed-g6"
+
+# Enable SPL signing by default
+SOCSEC_SIGN_ENABLE ?= "1"
+SOCSEC_SIGN_SOC ?= "2600"
+
 include conf/machine/include/soc-family.inc
 require conf/machine/include/aspeed.inc
 include conf/machine/include/arm/arch-armv7a.inc