build: check for patch and fix yasm check
build: check for patch and fix yasm check

Add configure checking for GNU patch tools and fixed configure
checking YASM to correct sequence.

Signed-off-by: Lim Siew Hoon <siew.hoon.lim@intel.com>

https://bugzilla.gnome.org/show_bug.cgi?id=756690

gbeauchesne/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi,gbeauchesne/gstreamer-vaapi