pxe: Move common parsing coding into pxe_util

Both the syslinux and pxe commands use essentially the same code to parse
and run extlinux.conf files. Move this into a common function.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Artem Lapkin <email2tema@gmail.com>
Tested-by: Artem Lapkin <email2tema@gmail.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/include/pxe_utils.h b/include/pxe_utils.h
index 6681442..0cae0da 100644
--- a/include/pxe_utils.h
+++ b/include/pxe_utils.h
@@ -202,4 +202,13 @@
 		   pxe_getfile_func getfile, void *userdata,
 		   bool allow_abs_path);
 
+/**
+ * pxe_process() - Process a PXE file through to boot
+ *
+ * @ctx: PXE context created with pxe_setup_ctx()
+ * @pxefile_addr_r: Address to load file
+ * @prompt: Force a prompt for the user
+ */
+int pxe_process(struct pxe_context *ctx, ulong pxefile_addr_r, bool prompt);
+
 #endif /* __PXE_UTILS_H */