SE/FS: Get rid of FULL_SYSTEM in the configs directory

configs/example/ruby_direct_test.py

@@ -38,9 +38,6 @@ addToPath('../ruby')
 
 import Ruby
 
-if buildEnv['FULL_SYSTEM']:
-    panic("This script requires system-emulation mode (*_SE).")
-
 # Get paths we might need.  It's expected this file is in m5/configs/example.
 config_path = os.path.dirname(os.path.abspath(__file__))
 config_root = os.path.dirname(config_path)