collectd: upgrade to 5.5.0

1. remove two patch glibc-2.20-compatiblity.patch and
0001-netlink-ensure-size_t-portability-in-DEBUG-statement.patch, which
have been merged into
2. update collectd-version.patch
3. redefine the collectd dependence
4. update the license, lots of components have been relicensed to the MIT
license, and The majority of plugins is licensed either under the "MIT License"
or the "GNU General Public License"
4. update the checksum

Signed-off-by: Roy Li <rongqing.li@windriver.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>