Add a make target and script that runs the secret generation.

The intention is to simplify building a complete bitstream as a user not
using the repo everyday. Also added a simple script that can provide
some guiding errors if some prerequisite is missing.

contrib/Makefile

@@ -56,6 +56,10 @@ flash:
 	-w /build/hw/application_fpga \
 	-it $(IMAGE) tillitis-iceprog /build/application_fpga.bin
 
+build-unlocked:
+	podman run --rm --mount type=bind,source="`pwd`/../hw/application_fpga",target=/build -w /build -it \
+	 $(IMAGE) make clean secret application_fpga.bin
+
 
 pull:
 	podman pull $(IMAGE)

contrib/build-unlocked.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+
+# Check if make is in the PATH
+if ! command -v make &> /dev/null
+then
+    echo "make is not installed or not in the PATH. Please install make and try again."
+    exit 1
+fi
+
+# Check if podman is in the PATH
+if ! command -v podman &> /dev/null
+then
+    echo "podman is not installed or not in the PATH. Please install podman and try again."
+    exit 1
+fi
+
+# Run the make command
+make build-unlocked
+exit 0