Need To add compile rule for test/dri2test

[gzg1984]

have done make in top folder and test folder
no compiling for dri2test.c triggered

Only produce .la file.

but there is main in dri2test.c. Why dont we produce the executable file directly?

gcc -g dri2test.c dri2util.c -I/usr/include/libdrm -ldrm -ldri2 -lX11