Removed relative paths from pkg-config files

Author: Mirco Bauer <meebey@meebey.net>

---
--- a/data/mono-cairo.pc.in
+++ b/data/mono-cairo.pc.in
@@ -1,5 +1,5 @@
-prefix=${pcfiledir}/../..
-exec_prefix=${pcfiledir}/../..
+prefix=@prefix@
+exec_prefix=${prefix}
 libdir=${prefix}/@reloc_libdir@
 includedir=${prefix}/include
 
--- a/data/mono.pc.in
+++ b/data/mono.pc.in
@@ -1,5 +1,5 @@
-prefix=${pcfiledir}/../..
-exec_prefix=${pcfiledir}/../..
+prefix=@prefix@
+exec_prefix=${prefix}
 libdir=${prefix}/@reloc_libdir@
 includedir=${prefix}/include/mono-@API_VER@
 sysconfdir=@sysconfdir@