tftpd: add hash file

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/tftpd/tftpd.hash

@@ -0,0 +1,2 @@
+# From https://www.kernel.org/pub/software/network/tftp/tftp-hpa/sha256sums.asc
+sha256	afee361df96a2f88344e191f6a25480fd714e1d28d176c3f10cc43fa206b718b	tftp-hpa-5.2.tar.xz