Lowercase a Windows library link for cross-compile purposes

(This was a common problem as I was getting LibOVR to compile. I
haven't actually tried cross-compiling OpenHMD.)

git-svn-id: https://s.snth.net/svn/neverball/trunk@3981 78b8d119-cf0a-0410-b17c-f493084dd1d7
Fix specifying LibOVR include directory multiple times

git-svn-id: https://s.snth.net/svn/neverball/trunk@3982 78b8d119-cf0a-0410-b17c-f493084dd1d7