[source] ramips: fix hg255d LED status support

[LEDE Commits]

mkresin pushed a commit to source.git, branch master:
https://git.lede-project.org/fb128057da92bdb6b2c4cd9ad9dd87637a4089b3

commit fb128057da92bdb6b2c4cd9ad9dd87637a4089b3
Author: David Yang <mmyangfl at gmail.com>
AuthorDate: Sat Sep 9 21:16:11 2017 +0800

    ramips: fix hg255d LED status support
    
    Use the green power LED for boot status indication.
    
    Source: https://my.oschina.net/osbin/blog/278782 Para 3
    
    Signed-off-by: David Yang <mmyangfl at gmail.com>
---
 target/linux/ramips/base-files/etc/diag.sh | 1 +
 1 file changed, 1 insertion(+)

diff --git a/target/linux/ramips/base-files/etc/diag.sh b/target/linux/ramips/base-files/etc/diag.sh
index 7517167..16c83f2 100644
--- a/target/linux/ramips/base-files/etc/diag.sh
+++ b/target/linux/ramips/base-files/etc/diag.sh
@@ -24,6 +24,7 @@ get_status_led() {
 	ex2700|\
 	ex3700|\
 	fonera20n|\
+	hg255d|\
 	kn|\
 	kn_rc|\
 	kn_rf|\