pxe: support linux entries for labels

Kernels can be specified using "linux" or "kernel" entry. The difference
is kernel is supposed to detect the type of file, but for u-boot both are
treated the same.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
diff --git a/common/cmd_pxe.c b/common/cmd_pxe.c
index 04094aa..946466e 100644
--- a/common/cmd_pxe.c
+++ b/common/cmd_pxe.c
@@ -631,6 +631,7 @@
 	T_TIMEOUT,
 	T_LABEL,
 	T_KERNEL,
+	T_LINUX,
 	T_APPEND,
 	T_INITRD,
 	T_LOCALBOOT,
@@ -659,6 +660,7 @@
 	{"prompt", T_PROMPT},
 	{"label", T_LABEL},
 	{"kernel", T_KERNEL},
+	{"linux", T_LINUX},
 	{"localboot", T_LOCALBOOT},
 	{"append", T_APPEND},
 	{"initrd", T_INITRD},
@@ -1027,6 +1029,7 @@
 			break;
 
 		case T_KERNEL:
+		case T_LINUX:
 			err = parse_sliteral(c, &label->kernel);
 			break;