buildroot

mplayer: disable LIVE555 Streaming Media

LIVE555 was installed on the build system and was recognized by configure:
Checking for LIVE555 Streaming Media libraries ... yes (using distribution version)

Later this led to a linker error:
ld: cannot find -lliveMedia

Disable LIVE555, since it's not available in Buildroot.

Signed-off-by: Markus Heidelberg <markus.heidelberg@web.de>