mplayer2: use autotools-brokensep (B = S)

The mplayer2 package does not support out of tree builds
and the do_configure step also tries to find the configure
script in the same build directory while the script lies in
the src directory.
This patch updates the builddir to point to the srcdir in
order to cope with the above issues.

Signed-off-by: Drew Moseley <drew_moseley@mentor.com>
Signed-off-by: Awais Belal <awais_belal@mentor.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>