drivers/x11: drop unneeded HAVE_X11_DRIVER check
drivers/x11: drop unneeded HAVE_X11_DRIVER check

Already handled in the Makefile which includes the drivers/x11 subdir.

Signed-off-by: Emil Velikov <4c996f2f093ddd0585a556460b4cc3ba555546ef@gmail.com>
Reviewed-by: Eric Anholt <96f164ad4d9b2b0dacf8ebee2bb1eeb3aa69adf1@anholt.net>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler