Replace config/config.awk with simple sed invocation

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13316

config/config.awk

@@ -1,15 +0,0 @@
-# Remove default preprocessor define's from config.h
-#   PACKAGE
-#   PACKAGE_BUGREPORT
-#   PACKAGE_NAME
-#   PACKAGE_STRING
-#   PACKAGE_TARNAME
-#   PACKAGE_VERSION
-#   STDC_HEADERS
-#   VERSION
-
-BEGIN { RS = "" ; FS = "\n" }     \
-	!/.#define PACKAGE./ &&   \
-	!/.#define VERSION./ &&   \
-	!/.#define STDC_HEADERS./ \
-	{ print $0"\n" }