scripts/bump_version.sh: update pkgconfig version

Bump the version number in pkgconfig/CMakeLists.txt so the package
config files stay in sync with the project VERSION.

This is Related to:
- aa4862a5e ("Bump the version number in CMakeLists.txt")

But changes were made to support CMake prior to version 3.0.

Signed-off-by: Bill Roberts <bill.roberts@arm.com>
diff --git a/scripts/bump_version.sh b/scripts/bump_version.sh
index 926e497..5c8e55d 100755
--- a/scripts/bump_version.sh
+++ b/scripts/bump_version.sh
@@ -67,6 +67,10 @@
   exit 1
 fi
 
+[ $VERBOSE ] && echo "Bumping PKGCONFIG_VERSION in pkgconfig/CMakeLists.txt"
+sed -e "s/PKGCONFIG_VERSION [0-9.]\{1,\}/PKGCONFIG_VERSION $VERSION/g" < pkgconfig/CMakeLists.txt > tmp
+mv tmp pkgconfig/CMakeLists.txt
+
 [ $VERBOSE ] && echo "Bumping VERSION in library/CMakeLists.txt"
 sed -e "s/ VERSION [0-9.]\{1,\}/ VERSION $VERSION/g" < library/CMakeLists.txt > tmp
 mv tmp library/CMakeLists.txt