xdp-tools: bump PKG_RELEASE
Increase PKG_RELEASE so buildbots pick up and rebuild the updated
package files.
Fixes: c752525511bb ("xdp-tools: add patch to fix stddef.h build issue")
Link: https://github.com/openwrt/openwrt/pull/21988
Signed-off-by: Nick Hainke <[email protected]>