build/glsl: fix android build v2

Commit 77a3efc6b907943903190b385fdf107c4acfcdca broke android build that
sets its own value for GLSL_SRCDIR before including Makefile.sources.
Patch moves overriding the value after include, this works as GLSL_SRCDIR
variable gets expanded only later.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
1 file changed