Move to /usr prefix.

- This is much more standard and replaces /image in sysa and is the
  standard in sysc (avoids many issues).
- GCC needs to have a file created for some unknown reason.
- Checksums updated.

sysc/gperf-3.1/checksums

@@ -0,0 +1 @@
+1f2a11dd9afd812a40ab44e5297ef375daddeda589c79d08be65958430c4ef82  /image/bin/gperf

sysc/gperf-3.1/gperf-3.1.sh

@@ -0,0 +1,19 @@
+# SPDX-FileCopyrightText: 2021 Andrius Štikonas <andrius@stikonas.eu>
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+src_prepare() {
+    find . -name '*.info*' -delete
+
+    for d in doc tests lib src; do
+        cd $d
+        ln -s ../aclocal.m4 aclocal.m4
+        autoreconf-2.69 -fi
+        cd ..
+    done
+    autoreconf-2.69 -fi
+}
+
+src_configure() {
+    ./configure --prefix="${PREFIX}"
+}