Initial work on keymap transforms for non-standard matrixes.

* Allows "gaps" for keyboards like Kyra.
* Allows keyboards with matrixes that don't map the logical key
  locations to have normal looking keymaps when defined.

app/boards/shields/kyria/Kconfig.shield

@@ -0,0 +1,5 @@
+# Copyright (c) 2020 Pete Johanson
+# SPDX-License-Identifier: MIT
+
+config SHIELD_KYRIA
+	def_bool $(shields_list_contains,kyria)