openmotif: Update SRC_URI and add libxft in depends

The file couldn't be found in the official repository and it seems
unmaintained as it had processing errors when trying to register to be
able to download the last release. Researching in the web a mirror has
been found and than we're using now this mirror so fetch works again.

During build test, from a clean tmp directory we found that libxft is
a hard dependency so we add it to depends list.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>