configure: look for libvdpau regardless of libavcodec
configure: look for libvdpau regardless of libavcodec

This uncomments the configure checks for HAVE_VDPAU. That way VDPAU can
be used even if libavcodec is missing or old.

vlc-mirror/vlc,vlc-mirror/vlc,vlc-mirror/vlc,jomanmuk/vlc-2.2,krichter722/vlc,vlc-mirror/vlc,shyamalschandra/vlc,jomanmuk/vlc-2.2,krichter722/vlc,jomanmuk/vlc-2.2,krichter722/vlc,shyamalschandra/vlc,jomanmuk/vlc-2.2,shyamalschandra/vlc,vlc-mirror/vlc,vlc-mirror/vlc,jomanmuk/vlc-2.2,xkfz007/vlc,krichter722/vlc,xkfz007/vlc,xkfz007/vlc,krichter722/vlc,shyamalschandra/vlc,krichter722/vlc,krichter722/vlc,jomanmuk/vlc-2.2,xkfz007/vlc,xkfz007/vlc,jomanmuk/vlc-2.2,xkfz007/vlc,shyamalschandra/vlc,xkfz007/vlc,vlc-mirror/vlc,shyamalschandra/vlc,shyamalschandra/vlc