php: update SRC_URI for new download location

* The old downloads location of http://www.php.net/distributions
  now points to a listing of all distributions and the mirrors or
  download locations where the sources can be downloaded.
* The new download location is http://museum.php.net/..... where
  the rest of the URL is based on the major version on PHP being
  downloaded.  This is a change from the previous download server
  which had a flattened directory structure so that all versions
  were available in a single location.
* To account for this change in the directory structure a variable
  called PHP_MAJVER is used based off of the PV to point the
  SRC_URI to the proper subdirectory.
* This issue wsa first noted by Joshua Vanderpool at
  Joshua.Vanderpool@raymondcorp.com and there was discussion at
  http://lists.openembedded.org/pipermail/openembedded-devel/2014-January/093757.html


* This patch has been commited to that master branch

Signed-off-by: Chase Maupin <chase.maupin@ti.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>