pxe: support include files at top-level

Include files outside of a menu were not getting included and parsed.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c
index b3c1f67..5949b24 100644
--- a/common/cmd_pxe.c
+++ b/common/cmd_pxe.c
@@ -1110,6 +1110,11 @@
 
 			break;
 
+		case T_INCLUDE:
+			err = handle_include(&p, b + ALIGN(strlen(b), 4), cfg,
+							nest_level + 1);
+			break;
+
 		case T_PROMPT:
 			err = parse_integer(&p, &cfg->prompt);
 			break;