package/bandwidthd: add license file

Use README as the license file until upstream provides one:
https://github.com/nroach44/bandwidthd/issues/2

While at it, also update indentation in hash file (two spaces)

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/bandwidthd/bandwidthd.hash

@@ -1,2 +1,3 @@
 # Locally calculated
-sha256 0270d0def6cc53c8d47d59a9dd093d51fbca1620adeef85c15e35a32010e26ab  bandwidthd-2.0.1-auto-r11.tar.gz
+sha256  0270d0def6cc53c8d47d59a9dd093d51fbca1620adeef85c15e35a32010e26ab  bandwidthd-2.0.1-auto-r11.tar.gz
+sha256  58573c40770e0c0b91f3eef8192952832321a344f66a4fb2d966095cbbfc86c2  README

package/bandwidthd/bandwidthd.mk

@@ -10,6 +10,7 @@ BANDWIDTHD_SITE = $(call github,nroach44,bandwidthd,v$(BANDWIDTHD_VERSION))
 # Specified as "any version of the GPL that is current as of your
 # download" by upstream.
 BANDWIDTHD_LICENSE = GPL
+BANDWIDTHD_LICENSE_FILES = README
 
 BANDWIDTHD_DEPENDENCIES = gd libpng libpcap host-pkgconf