Kconfig/bhp_*: add initial Kconfig modelling

sys/Kconfig

@@ -12,6 +12,7 @@ rsource "arduino/Kconfig"
 rsource "auto_init/Kconfig"
 rsource "base64/Kconfig"
 rsource "benchmark/Kconfig"
+rsource "bhp/Kconfig"
 rsource "bitfield/Kconfig"
 rsource "bloom/Kconfig"
 rsource "bus/Kconfig"

sys/bhp/Kconfig

@@ -0,0 +1,25 @@
+# Copyright (c) 2022 HAW Hamburg
+#
+# This file is subject to the terms and conditions of the GNU Lesser
+# General Public License v2.1. See the file LICENSE in the top level
+# directory for more details.
+#
+
+menu "Bottom Half Processor"
+
+config HAVE_BHP_IRQ_HANDLER
+    bool
+    select MODULE_BHP
+    help
+        "Indicates that a module exposes an IRQ Handler to be offloaded to a
+         Bottom Half Processor mechanism."
+
+config MODULE_BHP
+    bool
+
+config MODULE_BHP_EVENT
+    bool "Enable event based Bottom Half Processor implementation"
+    depends on MODULE_EVENT
+    depends on MODULE_BHP
+
+endmenu