glew: fix generation of glew.pc needed by mesa-demos

(From OE-Core rev: 0273f31d20f3e3c24e8b309f928595885eb04af2)

Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit d5bc211255599e88e54b2dd746b65651d10045f3)

Signed-off-by: Drew Moseley <drew_moseley@mentor.com>