Add .deps/, .libs/, and *.la to toplevel .gitignore

To avoid redundancies, this patch also removes .deps, .libs, and *.la
from .gitignore files in subdirectories.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/glsl/glcpp/.gitignore

@@ -5,7 +5,5 @@ glcpp-parse.c
 glcpp-parse.h
 *.o
 *.lo
-*.la
-.libs
 *~
 tests/*.out