Add getrevision.sh utility script

This allows to retrieve various data from SCM systems (git and svn) and
use them in the build process to better indicate which source was used.
For now only use it for the upstream (i.e. svn) revision number, which
was previously implemented by an awful line in the Makefile.

Corresponding to flashrom svn r1713.

Signed-off-by: David Hendricks <dhendrix@google.com>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/Makefile b/Makefile
index 6e41e5d..023c41d 100644
--- a/Makefile
+++ b/Makefile
@@ -326,7 +326,7 @@
 # of the checked out flashrom files.
 # Note to packagers: Any tree exported with "make export" or "make tarball"
 # will not require subversion. The downloadable snapshots are already exported.
-SVNVERSION := $(shell LC_ALL=C svnversion -cn . 2>/dev/null | sed -e "s/.*://" -e "s/\([0-9]*\).*/\1/" | grep "[0-9]" || LC_ALL=C svn info . 2>/dev/null | awk '/^Revision:/ {print $$2 }' | grep "[0-9]" || LC_ALL=C git svn info . 2>/dev/null | awk '/^Revision:/ {print $$2 }' | grep "[0-9]" || echo unknown)
+SVNVERSION := $(shell ./util/getrevision.sh -u)
 
 RELEASE := 0.9.7
 VERSION := $(RELEASE)-r$(SVNVERSION)