Update palmetto/habanero/firestone config flags.

    -Set BMC_AST2400 in config files to enable serial console
     and to enable SIO boot config functions

RTC:118752
diff --git a/openpower/configs/hostboot/firestone.config b/openpower/configs/hostboot/firestone.config
index 4b96cd9..cc59952 100755
--- a/openpower/configs/hostboot/firestone.config
+++ b/openpower/configs/hostboot/firestone.config
@@ -32,7 +32,7 @@
 
 # turn on console output
 set CONSOLE
-set CONSOLE_AST2400
+set BMC_AST2400
 
 # Enable Kingston dimm voltage workaround
 set KINGSTON_1_35_VOLT