tools: install the register definition files

Install the register definition files and use them by default in
intel_reg.

v2: remove redundant path check

Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Thomas Wood <thomas.wood@intel.com>
diff --git a/configure.ac b/configure.ac
index e4515f3..c7cb199 100644
--- a/configure.ac
+++ b/configure.ac
@@ -217,9 +217,10 @@
 
 files="broadwell cherryview haswell ivybridge sandybridge valleyview skylake"
 for file in $files; do
-	REGISTERS_EXTRA_DIST="$REGISTERS_EXTRA_DIST $file `tr '\n' ' ' < $srcdir/tools/registers/$file`"
+	REGISTER_FILES="$REGISTER_FILES $file `cat $srcdir/tools/registers/$file`"
 done
-AC_SUBST(REGISTERS_EXTRA_DIST)
+REGISTER_FILES=`echo $REGISTER_FILES | tr ' ' '\n' | sort -u | tr '\n' ' '`
+AC_SUBST(REGISTER_FILES)
 
 AC_CONFIG_FILES([
 		 Makefile