pixman: Fix C pre-processor issues in LEAF_MIPS32R2

Apply a patch which will be upstreamed soon to fix a problem with the C
pre-processor. This fixes a build failure in MIPS32r2 architectures.

Related:
	http://lists.freedesktop.org/archives/pixman/2014-September/003419.html

Bug report:
	https://bugs.freedesktop.org/show_bug.cgi?id=83358



Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>