Factor out ibex_pkg.sv into a separate core file

The ibex_pkg.sv file is effectively a "header" with useful defines;
we need them in ibex_tracer_pkg.sv, and in other places around Ibex.
Currently, the dependency between ibex_tracer_pkg.sv and ibex_pkg.sv
wasn't covered in a FuseSoC core file, leading to unstable behavior.

This patch adds this dependency by
- factoring out the ibex_pkg.sv file into a separate core file,
  ibex_pkg.core, and
- adding a dependency on the new ibex_pkg core to the ibex_tracer core.

ibex_core.core

@@ -9,8 +9,8 @@ filesets:
   files_rtl:
     depend:
       - lowrisc:prim:assert
+      - lowrisc:ibex:ibex_pkg
     files:
-      - rtl/ibex_pkg.sv
       - rtl/ibex_alu.sv
       - rtl/ibex_compressed_decoder.sv
       - rtl/ibex_controller.sv

ibex_pkg.core

@@ -0,0 +1,17 @@
+CAPI=2:
+# Copyright lowRISC contributors.
+# Licensed under the Apache License, Version 2.0, see LICENSE for details.
+# SPDX-License-Identifier: Apache-2.0
+name: "lowrisc:ibex:ibex_pkg:0.1"
+description: "Header package for Ibex"
+
+filesets:
+  files_rtl:
+    files:
+      - rtl/ibex_pkg.sv
+    file_type: systemVerilogSource
+
+targets:
+  default:
+    filesets:
+      - files_rtl

ibex_tracer.core

@@ -8,6 +8,7 @@ filesets:
   files_rtl:
     depend:
       - lowrisc:prim:assert
+      - lowrisc:ibex:ibex_pkg
     files:
       - rtl/ibex_tracer_pkg.sv
       - rtl/ibex_tracer.sv