Update SDL2 revsions.
Update SDL2 revsions.

This is the second attempt at fixing the SDL2 build.
This should fix the glibc and pnacl builds.

TBR=binji

Review URL: https://codereview.chromium.org/313803003

git-svn-id: 84b3587ce119b778414dcb50e18b7479aacf4f1d@1301 7dad1e8b-422e-d2af-fbf5-8013b78bd812

kuscsik/naclports,dtkav/naclports,kuscsik/naclports,kuscsik/naclports,kuscsik/naclports,Schibum/naclports,Schibum/naclports,yeyus/naclports,dtkav/naclports,dtkav/naclports,yeyus/naclports,kuscsik/naclports,Schibum/naclports,dtkav/naclports,yeyus/naclports,Schibum/naclports,yeyus/naclports,yeyus/naclports,dtkav/naclports,Schibum/naclports,yeyus/naclports,Schibum/naclports