Filter radeon pkgconfig file as do intel and nouveau
diff --git a/.gitignore b/.gitignore
index ba5440b..fbece64 100644
--- a/.gitignore
+++ b/.gitignore
@@ -38,6 +38,7 @@
 libdrm.pc
 libdrm_intel.pc
 libdrm_nouveau.pc
+libdrm_radeon.pc
 libtool
 ltmain.sh
 mach64.kld