tftp-hpa: add from OE-Classic, update and tidy up

* Update to 5.2
* Add patches from Fedora
* Add DESCRIPTION and better SUMMARY
* Make LICENSE more accurate
* Add LIC_FILES_CHKSUM
* Update ALTERNATIVE_* definitions
* Handle hardcoded paths in initscript

Much of this was done by Joe MacDonald <joe.macdonald@windriver.com>.

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>