coreutils: Add config.h to ptest package

coreutils: Add config.h to ptest package

This is needed by several tests during run on target

Fixes
grep: /usr/lib/coreutils/ptest/lib/config.h: No such file or directory
inotify-race.sh: skipped test: inotify is not supported

More tests are now passing

 ============================================================================
 Testsuite summary for GNU coreutils 9.4
 ============================================================================
 # TOTAL: 643
-# PASS:  509
-# SKIP:  131
+# PASS:  516
+# SKIP:  124

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>