modphp: add from OE-Classic, update to 5.3.14 and fix

* Use working SRC_URI
* Fix to use correct headers and apxs script for cross-compiling
* Enable threading
* Install headers and scripts for building extension modules
* Use proper variables instead of /etc, /usr/lib etc.
* Fix rpath QA issues
* Add LIC_FILES_CHKSUM
* Put apache config file into SRC_URI instead of referring to it using
  FILESDIR

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